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Re: [PPLetterpress] Re: Laser Engraved Photopolymer Plates

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  • Erik Desmyter
    Gerald, I understand the variable relief but not such a variable angle. To me it still is a very small round dot created by the UV light going through a very
    Message 1 of 29 , Oct 23, 2011
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      Gerald,

      I understand the variable relief but not such a variable angle. To me it still is a very small round dot created by the UV light going through a very small circle in the black film and hardening the polymer that can be exposed by that UV light bundle. I am still surprised at the 45 degrees on such a small halftone dot and I try to understand technically or optically why this would be so different to a letterform.

      Best regards,
      Erik


      > Eric
      >
      > These are halftone dots at 150 lpi not letterforms. They would show the
      > tiniest of surface image at extreme proximation and the shallowest of
      > relief and the foundation needed to support it. The least of impression
      > is all that is required to reproduce a halftone with accuracy to detail.
      > As I mentioned, the photopolymer process produces variable relief.
      >
      > Gerald
      > http://BielerPress.blogspot.com
      >
      > On 10/23/11 12:34 PM, Erik Desmyter wrote:
      >> Gerald,
      >>
      >> I agree that this is the main problem with lasers. However I am surprised to see here on this film based photopolymer http://www.flickr.com/photos/bielerpress/6272724517 an angle or slope around 45 degrees. That can result during inking with soft rollers and under pressure that the ink goes rather easy over the top surface on to the sides of the mountain what then gives no longer sharp printed edges. With tradition metal type those sides would be around 75 degrees I guess.
      >>
      >> Best regards,
      >> Erik
      >>
      >>
      >>> Scott
      >>>
      >>> Maybe a picture or two is worth a thousand words:
      >>>
      >>> http://www.flickr.com/photos/bielerpress/6272724517/in/photostream/#/photos/bielerpress/6272724517/in/photostream/lightbox/
      >>>
      >>> http://www.flickr.com/photos/bielerpress/6273250924/in/photostream/#/photos/bielerpress/6273250924/in/photostream/lightbox/
      >>>
      >>> These are microscopic views of the surface of a halftone image. This is
      >>> why photopolymer can provide such exquisite detail. The relief depth
      >>> between imaging of close proximity decreases with exposure and provides
      >>> structure.
      >>>
      >>> Gerald
      >>> http://BielerPress.blogspot.com
      >>>
      >>>
      >>> On 10/23/11 10:00 AM, Scott Rubel wrote:
      >>>> Gerald,
      >>>>
      >>>> Good thinking about all this. I certainly would want it to be a
      >>>> minimum of 2400, for one thing, but I have not known how to think
      >>>> about the other disadvantages.
      >>>>
      >>>> The thing that I hope for when I think about the potential of laser is
      >>>> straight sides to the raised type. I don't I understand why there
      >>>> would be a limit to the depth in a counter as opposed to any other
      >>>> part. My knowledge of lasers is based on mostly half- or 3/4-witted
      >>>> speculation mixed with fantasy, which is why I do not understand your
      >>>> last paragraph, but I trust your assessment.
      >>>>
      >>>> --Scott
      >>>>
      >>>> On Oct 22, 2011, at 10:57 PM, Gerald Lange wrote:
      >>>>
      >>>>> Scott
      >>>>>
      >>>>> I suspect that if cut just short of the floor of the plate rather
      >>>>> than down to the backing there would be no problem with the steel
      >>>>> reflecting. A more significant concern would be cutting through the
      >>>>> pre-exposed floor as plate stability would be sacrificed. Actually,
      >>>>> with this technique, the thinner the plate the better. All that
      >>>>>
      >>>>> I assume the identity of the plates themselves and the correct
      >>>>> timing for the exposure is a minor problem. 1200 dpi is still not
      >>>>> good enough, basically high-end laser printer quality. Imagesetter
      >>>>> quality at a minimum of 2400 dpi would be needed to match current
      >>>>> film based exposure.
      >>>>>
      >>>>> A major concern would be maintaining relative reverse relief depth,
      >>>>> which is fairly uniform when exposing photopolymer plates specified
      >>>>> for letterpress applications, no matter what the thickness of plate.
      >>>>> For instance, the relief depth of the counter of a small point size
      >>>>> lowercase e or o is not going to be open to the depth of the floor
      >>>>> of the plate. It is halted with maximum exposure at a specific
      >>>>> range, about .30 mm; relief depth is not uniform [which is actually
      >>>>> the best technical argument refuting the practice of extreme
      >>>>> impression]. I don't see how this could be controlled with a laser
      >>>>> cutter.
      >>>>>
      >>>>> Gerald
      >>>>> http://BielerPress.blogspot.com
      >>>>>
      >>>>>
      >>>>> --- In PPLetterpress@yahoogroups.com, Scott Rubel<scott@...> wrote:
      >>>>>> The website days it goes to 1200 dpi. If the coordinate tracking is
      >>>>>> accurate as it cuts, that should render pretty good six point type.
      >>>>>>
      >>>>>> It is hard to tell the quality of the laser, but I think I will ask
      >>>>>> them for a sample of steel backed polymer. I wonder how that works
      >>>>>> without the steel acting like a mirror.
      >>>>>>
      >>>>>> These laser beams can be unbelievable thin, if they are high quality.
      >>>>>> I work at a place where we make giant cameras for giant telescopes,
      >>>>>> and we order custom "slit masks" which are large sheets of aluminum
      >>>>>> with thousands of precision placed cuts in them. The cuts aren't much
      >>>>>> thicker than a hair, and you would think the laser is just moving
      >>>>>> along a path and cutting the slit, but in reality it cuts out the
      >>>>>> shape of the slit and almost microscopic blanks fall out of the metal
      >>>>>> every time a slit is cut. So if this Epilog Legend 36EXT machine is
      >>>>>> high quality, I would think six point type should work fine.
      >>>>>>
      >>>>>> --Scott
      >>>>>>
      >>>>>>
      >>>
      >
      >
      >
      > ------------------------------------
      >
      > Yahoo! Groups Links
      >
      >
      >
    • Gerald Lange
      Erik Not sure how to respond to this but imagine no relief as possibly cut by a laser. The structures would collapse under impression. Letterforms greatly
      Message 2 of 29 , Oct 23, 2011
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        Erik

        Not sure how to respond to this but imagine no relief as possibly cut by
        a laser. The structures would collapse under impression. Letterforms
        greatly differ in their surface structure. Counters, stems, serifs. And
        varying sizes. A relative relief helps provide support. In the
        punchcutting of type faces, varied relief is a characteristic as well.

        I don't know off hand what the slope of a 150 lpi halftone dot would be
        on a photomechanical engraving but I assume it would be much different
        that than of a metal typeface, though I have one of the last thorough
        print studies on this and will look it up and report back.

        Gerald
        http://BielerPress.blogspot.com

        On 10/23/11 1:05 PM, Erik Desmyter wrote:
        > Gerald,
        >
        > I understand the variable relief but not such a variable angle. To me it still is a very small round dot created by the UV light going through a very small circle in the black film and hardening the polymer that can be exposed by that UV light bundle. I am still surprised at the 45 degrees on such a small halftone dot and I try to understand technically or optically why this would be so different to a letterform.
        >
        > Best regards,
        > Erik
        >
        >
        >> Eric
        >>
        >> These are halftone dots at 150 lpi not letterforms. They would show the
        >> tiniest of surface image at extreme proximation and the shallowest of
        >> relief and the foundation needed to support it. The least of impression
        >> is all that is required to reproduce a halftone with accuracy to detail.
        >> As I mentioned, the photopolymer process produces variable relief.
        >>
        >> Gerald
        >> http://BielerPress.blogspot.com
        >>
        >> On 10/23/11 12:34 PM, Erik Desmyter wrote:
        >>> Gerald,
        >>>
        >>> I agree that this is the main problem with lasers. However I am surprised to see here on this film based photopolymer http://www.flickr.com/photos/bielerpress/6272724517 an angle or slope around 45 degrees. That can result during inking with soft rollers and under pressure that the ink goes rather easy over the top surface on to the sides of the mountain what then gives no longer sharp printed edges. With tradition metal type those sides would be around 75 degrees I guess.
        >>>
        >>> Best regards,
        >>> Erik
        >>>
        >>>
        >>>> Scott
        >>>>
        >>>> Maybe a picture or two is worth a thousand words:
        >>>>
        >>>> http://www.flickr.com/photos/bielerpress/6272724517/in/photostream/#/photos/bielerpress/6272724517/in/photostream/lightbox/
        >>>>
        >>>> http://www.flickr.com/photos/bielerpress/6273250924/in/photostream/#/photos/bielerpress/6273250924/in/photostream/lightbox/
        >>>>
        >>>> These are microscopic views of the surface of a halftone image. This is
        >>>> why photopolymer can provide such exquisite detail. The relief depth
        >>>> between imaging of close proximity decreases with exposure and provides
        >>>> structure.
        >>>>
        >>>> Gerald
        >>>> http://BielerPress.blogspot.com
        >>>>
        >>>>
        >>>> On 10/23/11 10:00 AM, Scott Rubel wrote:
        >>>>> Gerald,
        >>>>>
        >>>>> Good thinking about all this. I certainly would want it to be a
        >>>>> minimum of 2400, for one thing, but I have not known how to think
        >>>>> about the other disadvantages.
        >>>>>
        >>>>> The thing that I hope for when I think about the potential of laser is
        >>>>> straight sides to the raised type. I don't I understand why there
        >>>>> would be a limit to the depth in a counter as opposed to any other
        >>>>> part. My knowledge of lasers is based on mostly half- or 3/4-witted
        >>>>> speculation mixed with fantasy, which is why I do not understand your
        >>>>> last paragraph, but I trust your assessment.
        >>>>>
        >>>>> --Scott
        >>>>>
        >>>>> On Oct 22, 2011, at 10:57 PM, Gerald Lange wrote:
        >>>>>
        >>>>>> Scott
        >>>>>>
        >>>>>> I suspect that if cut just short of the floor of the plate rather
        >>>>>> than down to the backing there would be no problem with the steel
        >>>>>> reflecting. A more significant concern would be cutting through the
        >>>>>> pre-exposed floor as plate stability would be sacrificed. Actually,
        >>>>>> with this technique, the thinner the plate the better. All that
        >>>>>>
        >>>>>> I assume the identity of the plates themselves and the correct
        >>>>>> timing for the exposure is a minor problem. 1200 dpi is still not
        >>>>>> good enough, basically high-end laser printer quality. Imagesetter
        >>>>>> quality at a minimum of 2400 dpi would be needed to match current
        >>>>>> film based exposure.
        >>>>>>
        >>>>>> A major concern would be maintaining relative reverse relief depth,
        >>>>>> which is fairly uniform when exposing photopolymer plates specified
        >>>>>> for letterpress applications, no matter what the thickness of plate.
        >>>>>> For instance, the relief depth of the counter of a small point size
        >>>>>> lowercase e or o is not going to be open to the depth of the floor
        >>>>>> of the plate. It is halted with maximum exposure at a specific
        >>>>>> range, about .30 mm; relief depth is not uniform [which is actually
        >>>>>> the best technical argument refuting the practice of extreme
        >>>>>> impression]. I don't see how this could be controlled with a laser
        >>>>>> cutter.
        >>>>>>
        >>>>>> Gerald
        >>>>>> http://BielerPress.blogspot.com
        >>>>>>
        >>>>>>
        >>>>>> --- In PPLetterpress@yahoogroups.com, Scott Rubel<scott@...> wrote:
        >>>>>>> The website days it goes to 1200 dpi. If the coordinate tracking is
        >>>>>>> accurate as it cuts, that should render pretty good six point type.
        >>>>>>>
        >>>>>>> It is hard to tell the quality of the laser, but I think I will ask
        >>>>>>> them for a sample of steel backed polymer. I wonder how that works
        >>>>>>> without the steel acting like a mirror.
        >>>>>>>
        >>>>>>> These laser beams can be unbelievable thin, if they are high quality.
        >>>>>>> I work at a place where we make giant cameras for giant telescopes,
        >>>>>>> and we order custom "slit masks" which are large sheets of aluminum
        >>>>>>> with thousands of precision placed cuts in them. The cuts aren't much
        >>>>>>> thicker than a hair, and you would think the laser is just moving
        >>>>>>> along a path and cutting the slit, but in reality it cuts out the
        >>>>>>> shape of the slit and almost microscopic blanks fall out of the metal
        >>>>>>> every time a slit is cut. So if this Epilog Legend 36EXT machine is
        >>>>>>> high quality, I would think six point type should work fine.
        >>>>>>>
        >>>>>>> --Scott
        >>>>>>>
        >>>>>>>
        >>
        >>
        >> ------------------------------------
        >>
        >> Yahoo! Groups Links
        >>
        >>
        >>
        >
      • bielerpr
        Erik I checked through Letterpress Platemaking, a fairly intense technical reference on everything related to photo engraving, published in 1969 by the Library
        Message 3 of 29 , Oct 23, 2011
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          Erik

          I checked through Letterpress Platemaking, a fairly intense technical reference on everything related to photo engraving, published in 1969 by the Library of Industrial and Commercial Education and Training. It ends with the development of the photopolymer plate process and electronic engraving.

          Slope (angle of profile) is not a major concern but there is mention that "A good average profile for zinc etching has an angle of approximately 15-40% (average) from the verticle." It mentions that there is no particular standard and that a steeper slope in preferred in the Anglo-American sphere and a broad slope preferred on the Continent.

          In regard to photopolymer plates it suggests the obvious, extended exposure increases the profile and decreases the relief depth.


          Gerald
          http://BielerPress.blogspot.com

          --- In PPLetterpress@yahoogroups.com, Gerald Lange <Bieler@...> wrote:
          >
          > Erik
          >
          > Not sure how to respond to this but imagine no relief as possibly cut by
          > a laser. The structures would collapse under impression. Letterforms
          > greatly differ in their surface structure. Counters, stems, serifs. And
          > varying sizes. A relative relief helps provide support. In the
          > punchcutting of type faces, varied relief is a characteristic as well.
          >
          > I don't know off hand what the slope of a 150 lpi halftone dot would be
          > on a photomechanical engraving but I assume it would be much different
          > that than of a metal typeface, though I have one of the last thorough
          > print studies on this and will look it up and report back.
          >
          > Gerald
          > http://BielerPress.blogspot.com
          >
          > On 10/23/11 1:05 PM, Erik Desmyter wrote:
          > > Gerald,
          > >
          > > I understand the variable relief but not such a variable angle. To me it still is a very small round dot created by the UV light going through a very small circle in the black film and hardening the polymer that can be exposed by that UV light bundle. I am still surprised at the 45 degrees on such a small halftone dot and I try to understand technically or optically why this would be so different to a letterform.
          > >
          > > Best regards,
          > > Erik
          > >
          > >
          > >> Eric
          > >>
          > >> These are halftone dots at 150 lpi not letterforms. They would show the
          > >> tiniest of surface image at extreme proximation and the shallowest of
          > >> relief and the foundation needed to support it. The least of impression
          > >> is all that is required to reproduce a halftone with accuracy to detail.
          > >> As I mentioned, the photopolymer process produces variable relief.
          > >>
          > >> Gerald
          > >> http://BielerPress.blogspot.com
          > >>
          > >> On 10/23/11 12:34 PM, Erik Desmyter wrote:
          > >>> Gerald,
          > >>>
          > >>> I agree that this is the main problem with lasers. However I am surprised to see here on this film based photopolymer http://www.flickr.com/photos/bielerpress/6272724517 an angle or slope around 45 degrees. That can result during inking with soft rollers and under pressure that the ink goes rather easy over the top surface on to the sides of the mountain what then gives no longer sharp printed edges. With tradition metal type those sides would be around 75 degrees I guess.
          > >>>
          > >>> Best regards,
          > >>> Erik
          > >>>
          > >>>
          > >>>> Scott
          > >>>>
          > >>>> Maybe a picture or two is worth a thousand words:
          > >>>>
          > >>>> http://www.flickr.com/photos/bielerpress/6272724517/in/photostream/#/photos/bielerpress/6272724517/in/photostream/lightbox/
          > >>>>
          > >>>> http://www.flickr.com/photos/bielerpress/6273250924/in/photostream/#/photos/bielerpress/6273250924/in/photostream/lightbox/
          > >>>>
          > >>>> These are microscopic views of the surface of a halftone image. This is
          > >>>> why photopolymer can provide such exquisite detail. The relief depth
          > >>>> between imaging of close proximity decreases with exposure and provides
          > >>>> structure.
          > >>>>
          > >>>> Gerald
          > >>>> http://BielerPress.blogspot.com
          > >>>>
          > >>>>
          > >>>> On 10/23/11 10:00 AM, Scott Rubel wrote:
          > >>>>> Gerald,
          > >>>>>
          > >>>>> Good thinking about all this. I certainly would want it to be a
          > >>>>> minimum of 2400, for one thing, but I have not known how to think
          > >>>>> about the other disadvantages.
          > >>>>>
          > >>>>> The thing that I hope for when I think about the potential of laser is
          > >>>>> straight sides to the raised type. I don't I understand why there
          > >>>>> would be a limit to the depth in a counter as opposed to any other
          > >>>>> part. My knowledge of lasers is based on mostly half- or 3/4-witted
          > >>>>> speculation mixed with fantasy, which is why I do not understand your
          > >>>>> last paragraph, but I trust your assessment.
          > >>>>>
          > >>>>> --Scott
          > >>>>>
          > >>>>> On Oct 22, 2011, at 10:57 PM, Gerald Lange wrote:
          > >>>>>
          > >>>>>> Scott
          > >>>>>>
          > >>>>>> I suspect that if cut just short of the floor of the plate rather
          > >>>>>> than down to the backing there would be no problem with the steel
          > >>>>>> reflecting. A more significant concern would be cutting through the
          > >>>>>> pre-exposed floor as plate stability would be sacrificed. Actually,
          > >>>>>> with this technique, the thinner the plate the better. All that
          > >>>>>>
          > >>>>>> I assume the identity of the plates themselves and the correct
          > >>>>>> timing for the exposure is a minor problem. 1200 dpi is still not
          > >>>>>> good enough, basically high-end laser printer quality. Imagesetter
          > >>>>>> quality at a minimum of 2400 dpi would be needed to match current
          > >>>>>> film based exposure.
          > >>>>>>
          > >>>>>> A major concern would be maintaining relative reverse relief depth,
          > >>>>>> which is fairly uniform when exposing photopolymer plates specified
          > >>>>>> for letterpress applications, no matter what the thickness of plate.
          > >>>>>> For instance, the relief depth of the counter of a small point size
          > >>>>>> lowercase e or o is not going to be open to the depth of the floor
          > >>>>>> of the plate. It is halted with maximum exposure at a specific
          > >>>>>> range, about .30 mm; relief depth is not uniform [which is actually
          > >>>>>> the best technical argument refuting the practice of extreme
          > >>>>>> impression]. I don't see how this could be controlled with a laser
          > >>>>>> cutter.
          > >>>>>>
          > >>>>>> Gerald
          > >>>>>> http://BielerPress.blogspot.com
          > >>>>>>
          > >>>>>>
          > >>>>>> --- In PPLetterpress@yahoogroups.com, Scott Rubel<scott@> wrote:
          > >>>>>>> The website days it goes to 1200 dpi. If the coordinate tracking is
          > >>>>>>> accurate as it cuts, that should render pretty good six point type.
          > >>>>>>>
          > >>>>>>> It is hard to tell the quality of the laser, but I think I will ask
          > >>>>>>> them for a sample of steel backed polymer. I wonder how that works
          > >>>>>>> without the steel acting like a mirror.
          > >>>>>>>
          > >>>>>>> These laser beams can be unbelievable thin, if they are high quality.
          > >>>>>>> I work at a place where we make giant cameras for giant telescopes,
          > >>>>>>> and we order custom "slit masks" which are large sheets of aluminum
          > >>>>>>> with thousands of precision placed cuts in them. The cuts aren't much
          > >>>>>>> thicker than a hair, and you would think the laser is just moving
          > >>>>>>> along a path and cutting the slit, but in reality it cuts out the
          > >>>>>>> shape of the slit and almost microscopic blanks fall out of the metal
          > >>>>>>> every time a slit is cut. So if this Epilog Legend 36EXT machine is
          > >>>>>>> high quality, I would think six point type should work fine.
          > >>>>>>>
          > >>>>>>> --Scott
          > >>>>>>>
          > >>>>>>>
          > >>
          > >>
          > >> ------------------------------------
          > >>
          > >> Yahoo! Groups Links
          > >>
          > >>
          > >>
          > >
          >
        • Joe Lanich
          Hi, Sorry I am late to this conversation, but I have been using direct engrave polymer plates for letterpress for threes months or so now and experimenting
          Message 4 of 29 , Oct 24, 2011
          • 0 Attachment
            Hi, 

            Sorry I am late to this conversation, but I have been using direct engrave polymer plates for letterpress for threes months or so now and experimenting with other materials before that. While I do not consider myself to be a fine art printer, I do believe this process makes very acceptable printing plates. 

            I'd be happy to share my experiences with you if you have any questions. I am hesitant to put a link to my webpage describing the plates because I do have a profit motive (I am selling some of the plate material) and I don't want readers to believe I am here just shilling my products. I'll be honest with any questions, and there are pro's and con's to using the direct engrave polymer. I'd also be happy to perform any suggested test engravings on the material that would help to understand it's abilities. Like I said I have only been using it for three months and would be a fool to say I know everything. What I have seen has been very positive and has fit very well into my business. 

            Thanks for your time, 

            -Joe

            On Sun, Oct 23, 2011 at 11:46 PM, bielerpr <Bieler@...> wrote:
             

            Erik

            I checked through Letterpress Platemaking, a fairly intense technical reference on everything related to photo engraving, published in 1969 by the Library of Industrial and Commercial Education and Training. It ends with the development of the photopolymer plate process and electronic engraving.

            Slope (angle of profile) is not a major concern but there is mention that "A good average profile for zinc etching has an angle of approximately 15-40% (average) from the verticle." It mentions that there is no particular standard and that a steeper slope in preferred in the Anglo-American sphere and a broad slope preferred on the Continent.

            In regard to photopolymer plates it suggests the obvious, extended exposure increases the profile and decreases the relief depth.

            Gerald
            http://BielerPress.blogspot.com



            --- In PPLetterpress@yahoogroups.com, Gerald Lange <Bieler@...> wrote:
            >
            > Erik
            >
            > Not sure how to respond to this but imagine no relief as possibly cut by
            > a laser. The structures would collapse under impression. Letterforms
            > greatly differ in their surface structure. Counters, stems, serifs. And
            > varying sizes. A relative relief helps provide support. In the
            > punchcutting of type faces, varied relief is a characteristic as well.
            >
            > I don't know off hand what the slope of a 150 lpi halftone dot would be
            > on a photomechanical engraving but I assume it would be much different
            > that than of a metal typeface, though I have one of the last thorough
            > print studies on this and will look it up and report back.
            >
            > Gerald
            > http://BielerPress.blogspot.com
            >
            > On 10/23/11 1:05 PM, Erik Desmyter wrote:
            > > Gerald,
            > >
            > > I understand the variable relief but not such a variable angle. To me it still is a very small round dot created by the UV light going through a very small circle in the black film and hardening the polymer that can be exposed by that UV light bundle. I am still surprised at the 45 degrees on such a small halftone dot and I try to understand technically or optically why this would be so different to a letterform.
            > >
            > > Best regards,
            > > Erik
            > >
            > >
            > >> Eric
            > >>
            > >> These are halftone dots at 150 lpi not letterforms. They would show the
            > >> tiniest of surface image at extreme proximation and the shallowest of
            > >> relief and the foundation needed to support it. The least of impression
            > >> is all that is required to reproduce a halftone with accuracy to detail.
            > >> As I mentioned, the photopolymer process produces variable relief.
            > >>
            > >> Gerald
            > >> http://BielerPress.blogspot.com
            > >>
            > >> On 10/23/11 12:34 PM, Erik Desmyter wrote:
            > >>> Gerald,
            > >>>
            > >>> I agree that this is the main problem with lasers. However I am surprised to see here on this film based photopolymer http://www.flickr.com/photos/bielerpress/6272724517 an angle or slope around 45 degrees. That can result during inking with soft rollers and under pressure that the ink goes rather easy over the top surface on to the sides of the mountain what then gives no longer sharp printed edges. With tradition metal type those sides would be around 75 degrees I guess.
            > >>>
            > >>> Best regards,
            > >>> Erik
            > >>>
            > >>>
            > >>>> Scott
            > >>>>
            > >>>> Maybe a picture or two is worth a thousand words:
            > >>>>
            > >>>> http://www.flickr.com/photos/bielerpress/6272724517/in/photostream/#/photos/bielerpress/6272724517/in/photostream/lightbox/
            > >>>>
            > >>>> http://www.flickr.com/photos/bielerpress/6273250924/in/photostream/#/photos/bielerpress/6273250924/in/photostream/lightbox/
            > >>>>
            > >>>> These are microscopic views of the surface of a halftone image. This is
            > >>>> why photopolymer can provide such exquisite detail. The relief depth
            > >>>> between imaging of close proximity decreases with exposure and provides
            > >>>> structure.
            > >>>>
            > >>>> Gerald
            > >>>> http://BielerPress.blogspot.com
            > >>>>
            > >>>>
            > >>>> On 10/23/11 10:00 AM, Scott Rubel wrote:
            > >>>>> Gerald,
            > >>>>>
            > >>>>> Good thinking about all this. I certainly would want it to be a
            > >>>>> minimum of 2400, for one thing, but I have not known how to think
            > >>>>> about the other disadvantages.
            > >>>>>
            > >>>>> The thing that I hope for when I think about the potential of laser is
            > >>>>> straight sides to the raised type. I don't I understand why there
            > >>>>> would be a limit to the depth in a counter as opposed to any other
            > >>>>> part. My knowledge of lasers is based on mostly half- or 3/4-witted
            > >>>>> speculation mixed with fantasy, which is why I do not understand your
            > >>>>> last paragraph, but I trust your assessment.
            > >>>>>
            > >>>>> --Scott
            > >>>>>
            > >>>>> On Oct 22, 2011, at 10:57 PM, Gerald Lange wrote:
            > >>>>>
            > >>>>>> Scott
            > >>>>>>
            > >>>>>> I suspect that if cut just short of the floor of the plate rather
            > >>>>>> than down to the backing there would be no problem with the steel
            > >>>>>> reflecting. A more significant concern would be cutting through the
            > >>>>>> pre-exposed floor as plate stability would be sacrificed. Actually,
            > >>>>>> with this technique, the thinner the plate the better. All that
            > >>>>>>
            > >>>>>> I assume the identity of the plates themselves and the correct
            > >>>>>> timing for the exposure is a minor problem. 1200 dpi is still not
            > >>>>>> good enough, basically high-end laser printer quality. Imagesetter
            > >>>>>> quality at a minimum of 2400 dpi would be needed to match current
            > >>>>>> film based exposure.
            > >>>>>>
            > >>>>>> A major concern would be maintaining relative reverse relief depth,
            > >>>>>> which is fairly uniform when exposing photopolymer plates specified
            > >>>>>> for letterpress applications, no matter what the thickness of plate.
            > >>>>>> For instance, the relief depth of the counter of a small point size
            > >>>>>> lowercase e or o is not going to be open to the depth of the floor
            > >>>>>> of the plate. It is halted with maximum exposure at a specific
            > >>>>>> range, about .30 mm; relief depth is not uniform [which is actually
            > >>>>>> the best technical argument refuting the practice of extreme
            > >>>>>> impression]. I don't see how this could be controlled with a laser
            > >>>>>> cutter.
            > >>>>>>
            > >>>>>> Gerald
            > >>>>>> http://BielerPress.blogspot.com
            > >>>>>>
            > >>>>>>
            > >>>>>> --- In PPLetterpress@yahoogroups.com, Scott Rubel<scott@> wrote:
            > >>>>>>> The website days it goes to 1200 dpi. If the coordinate tracking is
            > >>>>>>> accurate as it cuts, that should render pretty good six point type.
            > >>>>>>>
            > >>>>>>> It is hard to tell the quality of the laser, but I think I will ask
            > >>>>>>> them for a sample of steel backed polymer. I wonder how that works
            > >>>>>>> without the steel acting like a mirror.
            > >>>>>>>
            > >>>>>>> These laser beams can be unbelievable thin, if they are high quality.
            > >>>>>>> I work at a place where we make giant cameras for giant telescopes,
            > >>>>>>> and we order custom "slit masks" which are large sheets of aluminum
            > >>>>>>> with thousands of precision placed cuts in them. The cuts aren't much
            > >>>>>>> thicker than a hair, and you would think the laser is just moving
            > >>>>>>> along a path and cutting the slit, but in reality it cuts out the
            > >>>>>>> shape of the slit and almost microscopic blanks fall out of the metal
            > >>>>>>> every time a slit is cut. So if this Epilog Legend 36EXT machine is
            > >>>>>>> high quality, I would think six point type should work fine.
            > >>>>>>>
            > >>>>>>> --Scott
            > >>>>>>>
            > >>>>>>>
            > >>
            > >>
            > >> ------------------------------------
            > >>
            > >> Yahoo! Groups Links
            > >>
            > >>
            > >>
            > >
            >


          • Scott Rubel
            Joe, Thank you for volunteering information. I would like to hear more of your experience with this. Acceptable sound different to me than excellent, so I
            Message 5 of 29 , Oct 24, 2011
            • 0 Attachment
              Joe,

              Thank you for volunteering information. I would like to hear more of your experience with this. "Acceptable" sound different to me than "excellent," so I would like to know what sorts of jobs you produce. What machine are you using?

              --Scott

              On Oct 24, 2011, at 6:04 PM, Joe Lanich wrote:



              Hi, 

              Sorry I am late to this conversation, but I have been using direct engrave polymer plates for letterpress for threes months or so now and experimenting with other materials before that. While I do not consider myself to be a fine art printer, I do believe this process makes very acceptable printing plates. 

              I'd be happy to share my experiences with you if you have any questions. I am hesitant to put a link to my webpage describing the plates because I do have a profit motive (I am selling some of the plate material) and I don't want readers to believe I am here just shilling my products. I'll be honest with any questions, and there are pro's and con's to using the direct engrave polymer. I'd also be happy to perform any suggested test engravings on the material that would help to understand it's abilities. Like I said I have only been using it for three months and would be a fool to say I know everything. What I have seen has been very positive and has fit very well into my business. 

              Thanks for your time, 

              -Joe

              On Sun, Oct 23, 2011 at 11:46 PM, bielerpr <Bieler@...> wrote:
               

              Erik

              I checked through Letterpress Platemaking, a fairly intense technical reference on everything related to photo engraving, published in 1969 by the Library of Industrial and Commercial Education and Training. It ends with the development of the photopolymer plate process and electronic engraving.

              Slope (angle of profile) is not a major concern but there is mention that "A good average profile for zinc etching has an angle of approximately 15-40% (average) from the verticle." It mentions that there is no particular standard and that a steeper slope in preferred in the Anglo-American sphere and a broad slope preferred on the Continent.

              In regard to photopolymer plates it suggests the obvious, extended exposure increases the profile and decreases the relief depth.

              Gerald
              http://BielerPress.blogspot.com



              --- In PPLetterpress@yahoogroups.com, Gerald Lange <Bieler@...> wrote:
              >
              > Erik
              > 
              > Not sure how to respond to this but imagine no relief as possibly cut by 
              > a laser. The structures would collapse under impression. Letterforms 
              > greatly differ in their surface structure. Counters, stems, serifs. And 
              > varying sizes. A relative relief helps provide support. In the 
              > punchcutting of type faces, varied relief is a characteristic as well.
              > 
              > I don't know off hand what the slope of a 150 lpi halftone dot would be 
              > on a photomechanical engraving but I assume it would be much different 
              > that than of a metal typeface, though I have one of the last thorough 
              > print studies on this and will look it up and report back.
              > 
              > Gerald
              > http://BielerPress.blogspot.com
              > 
              > On 10/23/11 1:05 PM, Erik Desmyter wrote:
              > > Gerald,
              > >
              > > I understand the variable relief but not such a variable angle. To me it still is a very small round dot created by the UV light going through a very small circle in the black film and hardening the polymer that can be exposed by that UV light bundle. I am still surprised at the 45 degrees on such a small halftone dot and I try to understand technically or optically why this would be so different to a letterform.
              > >
              > > Best regards,
              > > Erik
              > >
              > >
              > >> Eric
              > >>
              > >> These are halftone dots at 150 lpi not letterforms. They would show the
              > >> tiniest of surface image at extreme proximation and the shallowest of
              > >> relief and the foundation needed to support it. The least of impression
              > >> is all that is required to reproduce a halftone with accuracy to detail.
              > >> As I mentioned, the photopolymer process produces variable relief.
              > >>
              > >> Gerald
              > >> http://BielerPress.blogspot.com
              > >>
              > >> On 10/23/11 12:34 PM, Erik Desmyter wrote:
              > >>> Gerald,
              > >>>
              > >>> I agree that this is the main problem with lasers. However I am surprised to see here on this film based photopolymer http://www.flickr.com/photos/bielerpress/6272724517an angle or slope around 45 degrees. That can result during inking with soft rollers and under pressure that the ink goes rather easy over the top surface on to the sides of the mountain what then gives no longer sharp printed edges. With tradition metal type those sides would be around 75 degrees I guess.
              > >>>
              > >>> Best regards,
              > >>> Erik
              > >>>
              > >>>
              > >>>> Scott
              > >>>>
              > >>>> Maybe a picture or two is worth a thousand words:
              > >>>>
              > >>>> http://www.flickr.com/photos/bielerpress/6272724517/in/photostream/#/photos/bielerpress/6272724517/in/photostream/lightbox/
              > >>>>
              > >>>> http://www.flickr.com/photos/bielerpress/6273250924/in/photostream/#/photos/bielerpress/6273250924/in/photostream/lightbox/
              > >>>>
              > >>>> These are microscopic views of the surface of a halftone image. This is
              > >>>> why photopolymer can provide such exquisite detail. The relief depth
              > >>>> between imaging of close proximity decreases with exposure and provides
              > >>>> structure.
              > >>>>
              > >>>> Gerald
              > >>>> http://BielerPress.blogspot.com
              > >>>>
              > >>>>
              > >>>> On 10/23/11 10:00 AM, Scott Rubel wrote:
              > >>>>> Gerald,
              > >>>>>
              > >>>>> Good thinking about all this. I certainly would want it to be a
              > >>>>> minimum of 2400, for one thing, but I have not known how to think
              > >>>>> about the other disadvantages.
              > >>>>>
              > >>>>> The thing that I hope for when I think about the potential of laser is
              > >>>>> straight sides to the raised type. I don't I understand why there
              > >>>>> would be a limit to the depth in a counter as opposed to any other
              > >>>>> part. My knowledge of lasers is based on mostly half- or 3/4-witted
              > >>>>> speculation mixed with fantasy, which is why I do not understand your
              > >>>>> last paragraph, but I trust your assessment.
              > >>>>>
              > >>>>> --Scott
              > >>>>>
              > >>>>> On Oct 22, 2011, at 10:57 PM, Gerald Lange wrote:
              > >>>>>
              > >>>>>> Scott
              > >>>>>>
              > >>>>>> I suspect that if cut just short of the floor of the plate rather
              > >>>>>> than down to the backing there would be no problem with the steel
              > >>>>>> reflecting. A more significant concern would be cutting through the
              > >>>>>> pre-exposed floor as plate stability would be sacrificed. Actually,
              > >>>>>> with this technique, the thinner the plate the better. All that
              > >>>>>>
              > >>>>>> I assume the identity of the plates themselves and the correct
              > >>>>>> timing for the exposure is a minor problem. 1200 dpi is still not
              > >>>>>> good enough, basically high-end laser printer quality. Imagesetter
              > >>>>>> quality at a minimum of 2400 dpi would be needed to match current
              > >>>>>> film based exposure.
              > >>>>>>
              > >>>>>> A major concern would be maintaining relative reverse relief depth,
              > >>>>>> which is fairly uniform when exposing photopolymer plates specified
              > >>>>>> for letterpress applications, no matter what the thickness of plate.
              > >>>>>> For instance, the relief depth of the counter of a small point size
              > >>>>>> lowercase e or o is not going to be open to the depth of the floor
              > >>>>>> of the plate. It is halted with maximum exposure at a specific
              > >>>>>> range, about .30 mm; relief depth is not uniform [which is actually
              > >>>>>> the best technical argument refuting the practice of extreme
              > >>>>>> impression]. I don't see how this could be controlled with a laser
              > >>>>>> cutter.
              > >>>>>>
              > >>>>>> Gerald
              > >>>>>> http://BielerPress.blogspot.com
              > >>>>>>
              > >>>>>>
              > >>>>>> --- In PPLetterpress@yahoogroups.com, Scott Rubel<scott@> wrote:
              > >>>>>>> The website days it goes to 1200 dpi. If the coordinate tracking is
              > >>>>>>> accurate as it cuts, that should render pretty good six point type.
              > >>>>>>>
              > >>>>>>> It is hard to tell the quality of the laser, but I think I will ask
              > >>>>>>> them for a sample of steel backed polymer. I wonder how that works
              > >>>>>>> without the steel acting like a mirror.
              > >>>>>>>
              > >>>>>>> These laser beams can be unbelievable thin, if they are high quality.
              > >>>>>>> I work at a place where we make giant cameras for giant telescopes,
              > >>>>>>> and we order custom "slit masks" which are large sheets of aluminum
              > >>>>>>> with thousands of precision placed cuts in them. The cuts aren't much
              > >>>>>>> thicker than a hair, and you would think the laser is just moving
              > >>>>>>> along a path and cutting the slit, but in reality it cuts out the
              > >>>>>>> shape of the slit and almost microscopic blanks fall out of the metal
              > >>>>>>> every time a slit is cut. So if this Epilog Legend 36EXT machine is
              > >>>>>>> high quality, I would think six point type should work fine.
              > >>>>>>>
              > >>>>>>> --Scott
              > >>>>>>>
              > >>>>>>>
              > >>
              > >>
              > >> ------------------------------------
              > >>
              > >> Yahoo! Groups Links
              > >>
              > >>
              > >>
              > >
              >






            • Joe Lanich
              Scott, You will have to excuse my adjectives. I try to remain humble because I know I am still young and I still have much to learn. I don t want to oversell
              Message 6 of 29 , Oct 25, 2011
              • 0 Attachment
                Scott, 

                You will have to excuse my adjectives. I try to remain humble because I know I am still young and I still have much to learn. I don't want to oversell anything on a mailing list created by a man that prints pieces such as this: http://www.flickr.com/photos/bielerpress/5288736711/

                For the work we do (invites, coasters, greeting cards, etc) I would say this direct engrave polymer is excellent. You can find photos of our work here: http://www.laughingowlpress.com/work/. The photos on that page are not all inclusive to this direct engrave material. Some of the work was with conventional photopolymer, laser engravings of MDF and delrin, and type. Now we use the direct engrave polymer exclusively. Using the direct engrave process allows us to go from computer to plate in one step with minimal equipment investment. It has shortened our lead times and lowered our cost compared to when we had plates made offsite.  

                The laser engraver we have is a 40watt Rabbit 6040. You can find it here: http://www.rabbitlaserusa.com/laser_RL6040.asp . You can use any engraver you wish. For this direct engrave polymer we run ours at 28% power, so you could even have a lower wattage of laser and still have success. In the end the machine you buy will affect both your quality of engraving and ease of use. My biggest gripe is the import control software for our laser is clunky, but it works. It likes vector files the most. 

                The engraving does leave a slope on the engraving, you can see a picture of it on the briarpress.org thread about this material. 

                Thank you for your questions. They greatly help with understanding the material. I look forward to more. 

                -Joe


                On Mon, Oct 24, 2011 at 11:45 PM, Scott Rubel <scott@...> wrote:
                 

                Joe,


                Thank you for volunteering information. I would like to hear more of your experience with this. "Acceptable" sound different to me than "excellent," so I would like to know what sorts of jobs you produce. What machine are you using?

                --Scott

                On Oct 24, 2011, at 6:04 PM, Joe Lanich wrote:



                Hi, 

                Sorry I am late to this conversation, but I have been using direct engrave polymer plates for letterpress for threes months or so now and experimenting with other materials before that. While I do not consider myself to be a fine art printer, I do believe this process makes very acceptable printing plates. 

                I'd be happy to share my experiences with you if you have any questions. I am hesitant to put a link to my webpage describing the plates because I do have a profit motive (I am selling some of the plate material) and I don't want readers to believe I am here just shilling my products. I'll be honest with any questions, and there are pro's and con's to using the direct engrave polymer. I'd also be happy to perform any suggested test engravings on the material that would help to understand it's abilities. Like I said I have only been using it for three months and would be a fool to say I know everything. What I have seen has been very positive and has fit very well into my business. 

                Thanks for your time, 

                -Joe

                On Sun, Oct 23, 2011 at 11:46 PM, bielerpr <Bieler@...> wrote:
                 

                Erik

                I checked through Letterpress Platemaking, a fairly intense technical reference on everything related to photo engraving, published in 1969 by the Library of Industrial and Commercial Education and Training. It ends with the development of the photopolymer plate process and electronic engraving.

                Slope (angle of profile) is not a major concern but there is mention that "A good average profile for zinc etching has an angle of approximately 15-40% (average) from the verticle." It mentions that there is no particular standard and that a steeper slope in preferred in the Anglo-American sphere and a broad slope preferred on the Continent.

                In regard to photopolymer plates it suggests the obvious, extended exposure increases the profile and decreases the relief depth.

                Gerald
                http://BielerPress.blogspot.com



                --- In PPLetterpress@yahoogroups.com, Gerald Lange <Bieler@...> wrote:
                >
                > Erik
                > 
                > Not sure how to respond to this but imagine no relief as possibly cut by 
                > a laser. The structures would collapse under impression. Letterforms 
                > greatly differ in their surface structure. Counters, stems, serifs. And 
                > varying sizes. A relative relief helps provide support. In the 
                > punchcutting of type faces, varied relief is a characteristic as well.
                > 
                > I don't know off hand what the slope of a 150 lpi halftone dot would be 
                > on a photomechanical engraving but I assume it would be much different 
                > that than of a metal typeface, though I have one of the last thorough 
                > print studies on this and will look it up and report back.
                > 
                > Gerald
                > http://BielerPress.blogspot.com
                > 
                > On 10/23/11 1:05 PM, Erik Desmyter wrote:
                > > Gerald,
                > >
                > > I understand the variable relief but not such a variable angle. To me it still is a very small round dot created by the UV light going through a very small circle in the black film and hardening the polymer that can be exposed by that UV light bundle. I am still surprised at the 45 degrees on such a small halftone dot and I try to understand technically or optically why this would be so different to a letterform.
                > >
                > > Best regards,
                > > Erik
                > >
                > >
                > >> Eric
                > >>
                > >> These are halftone dots at 150 lpi not letterforms. They would show the
                > >> tiniest of surface image at extreme proximation and the shallowest of
                > >> relief and the foundation needed to support it. The least of impression
                > >> is all that is required to reproduce a halftone with accuracy to detail.
                > >> As I mentioned, the photopolymer process produces variable relief.
                > >>
                > >> Gerald
                > >> http://BielerPress.blogspot.com
                > >>
                > >> On 10/23/11 12:34 PM, Erik Desmyter wrote:
                > >>> Gerald,
                > >>>
                > >>> I agree that this is the main problem with lasers. However I am surprised to see here on this film based photopolymer http://www.flickr.com/photos/bielerpress/6272724517an angle or slope around 45 degrees. That can result during inking with soft rollers and under pressure that the ink goes rather easy over the top surface on to the sides of the mountain what then gives no longer sharp printed edges. With tradition metal type those sides would be around 75 degrees I guess.

                > >>>
                > >>> Best regards,
                > >>> Erik
                > >>>
                > >>>
                > >>>> Scott
                > >>>>
                > >>>> Maybe a picture or two is worth a thousand words:
                > >>>>
                > >>>> http://www.flickr.com/photos/bielerpress/6272724517/in/photostream/#/photos/bielerpress/6272724517/in/photostream/lightbox/
                > >>>>
                > >>>> http://www.flickr.com/photos/bielerpress/6273250924/in/photostream/#/photos/bielerpress/6273250924/in/photostream/lightbox/
                > >>>>
                > >>>> These are microscopic views of the surface of a halftone image. This is
                > >>>> why photopolymer can provide such exquisite detail. The relief depth
                > >>>> between imaging of close proximity decreases with exposure and provides
                > >>>> structure.
                > >>>>
                > >>>> Gerald
                > >>>> http://BielerPress.blogspot.com
                > >>>>
                > >>>>
                > >>>> On 10/23/11 10:00 AM, Scott Rubel wrote:
                > >>>>> Gerald,
                > >>>>>
                > >>>>> Good thinking about all this. I certainly would want it to be a
                > >>>>> minimum of 2400, for one thing, but I have not known how to think
                > >>>>> about the other disadvantages.
                > >>>>>
                > >>>>> The thing that I hope for when I think about the potential of laser is
                > >>>>> straight sides to the raised type. I don't I understand why there
                > >>>>> would be a limit to the depth in a counter as opposed to any other
                > >>>>> part. My knowledge of lasers is based on mostly half- or 3/4-witted
                > >>>>> speculation mixed with fantasy, which is why I do not understand your
                > >>>>> last paragraph, but I trust your assessment.
                > >>>>>
                > >>>>> --Scott
                > >>>>>
                > >>>>> On Oct 22, 2011, at 10:57 PM, Gerald Lange wrote:
                > >>>>>
                > >>>>>> Scott
                > >>>>>>
                > >>>>>> I suspect that if cut just short of the floor of the plate rather
                > >>>>>> than down to the backing there would be no problem with the steel
                > >>>>>> reflecting. A more significant concern would be cutting through the
                > >>>>>> pre-exposed floor as plate stability would be sacrificed. Actually,
                > >>>>>> with this technique, the thinner the plate the better. All that
                > >>>>>>
                > >>>>>> I assume the identity of the plates themselves and the correct
                > >>>>>> timing for the exposure is a minor problem. 1200 dpi is still not
                > >>>>>> good enough, basically high-end laser printer quality. Imagesetter
                > >>>>>> quality at a minimum of 2400 dpi would be needed to match current
                > >>>>>> film based exposure.
                > >>>>>>
                > >>>>>> A major concern would be maintaining relative reverse relief depth,
                > >>>>>> which is fairly uniform when exposing photopolymer plates specified
                > >>>>>> for letterpress applications, no matter what the thickness of plate.
                > >>>>>> For instance, the relief depth of the counter of a small point size
                > >>>>>> lowercase e or o is not going to be open to the depth of the floor
                > >>>>>> of the plate. It is halted with maximum exposure at a specific
                > >>>>>> range, about .30 mm; relief depth is not uniform [which is actually
                > >>>>>> the best technical argument refuting the practice of extreme
                > >>>>>> impression]. I don't see how this could be controlled with a laser
                > >>>>>> cutter.
                > >>>>>>
                > >>>>>> Gerald
                > >>>>>> http://BielerPress.blogspot.com
                > >>>>>>
                > >>>>>>
                > >>>>>> --- In PPLetterpress@yahoogroups.com, Scott Rubel<scott@> wrote:
                > >>>>>>> The website days it goes to 1200 dpi. If the coordinate tracking is
                > >>>>>>> accurate as it cuts, that should render pretty good six point type.
                > >>>>>>>
                > >>>>>>> It is hard to tell the quality of the laser, but I think I will ask
                > >>>>>>> them for a sample of steel backed polymer. I wonder how that works
                > >>>>>>> without the steel acting like a mirror.
                > >>>>>>>
                > >>>>>>> These laser beams can be unbelievable thin, if they are high quality.
                > >>>>>>> I work at a place where we make giant cameras for giant telescopes,
                > >>>>>>> and we order custom "slit masks" which are large sheets of aluminum
                > >>>>>>> with thousands of precision placed cuts in them. The cuts aren't much
                > >>>>>>> thicker than a hair, and you would think the laser is just moving
                > >>>>>>> along a path and cutting the slit, but in reality it cuts out the
                > >>>>>>> shape of the slit and almost microscopic blanks fall out of the metal
                > >>>>>>> every time a slit is cut. So if this Epilog Legend 36EXT machine is
                > >>>>>>> high quality, I would think six point type should work fine.
                > >>>>>>>
                > >>>>>>> --Scott
                > >>>>>>>
                > >>>>>>>
                > >>
                > >>
                > >> ------------------------------------
                > >>
                > >> Yahoo! Groups Links
                > >>
                > >>
                > >>
                > >
                >







              • Scott Rubel
                This is informative. You do some fun work. I looked at the link and it seems like a wonderful machine, except for the scanning precision of 50-1000. I m not
                Message 7 of 29 , Oct 25, 2011
                • 0 Attachment
                  This is informative. You do some fun work.

                  I looked at the link and it seems like a wonderful machine, except for the "scanning precision" of 50-1000. I'm not sure what that means. Is that the same as maximum resolution? If so, I wonder why they would not want to take full advantage of what a laser is capable of.

                  In the compatible software category, it does not include Illustrator or InDesign. You said it likes vector files best, so do you make everything in CorelDraw (which I didn't even know was sill around)?

                  --Scot

                  On Oct 25, 2011, at 5:46 AM, Joe Lanich wrote:



                  Scott, 

                  You will have to excuse my adjectives. I try to remain humble because I know I am still young and I still have much to learn. I don't want to oversell anything on a mailing list created by a man that prints pieces such as this: http://www.flickr.com/photos/bielerpress/5288736711/

                  For the work we do (invites, coasters, greeting cards, etc) I would say this direct engrave polymer is excellent. You can find photos of our work here: http://www.laughingowlpress.com/work/. The photos on that page are not all inclusive to this direct engrave material. Some of the work was with conventional photopolymer, laser engravings of MDF and delrin, and type. Now we use the direct engrave polymer exclusively. Using the direct engrave process allows us to go from computer to plate in one step with minimal equipment investment. It has shortened our lead times and lowered our cost compared to when we had plates made offsite.  

                  The laser engraver we have is a 40watt Rabbit 6040. You can find it here: http://www.rabbitlaserusa.com/laser_RL6040.asp . You can use any engraver you wish. For this direct engrave polymer we run ours at 28% power, so you could even have a lower wattage of laser and still have success. In the end the machine you buy will affect both your quality of engraving and ease of use. My biggest gripe is the import control software for our laser is clunky, but it works. It likes vector files the most. 

                  The engraving does leave a slope on the engraving, you can see a picture of it on the briarpress.org thread about this material. 

                  Thank you for your questions. They greatly help with understanding the material. I look forward to more. 

                  -Joe






                • Silber MaiKätzchen
                  I did some 4 point about a week ago, (Palitino,) and it came out fine. Most of my typography is aimed at ease of reading;but, this was for a lawyer more
                  Message 8 of 29 , Oct 25, 2011
                  • 0 Attachment
                    I did some 4 point about a week ago, (Palitino,) and
                    it came out fine. Most of my typography is aimed at
                    ease of reading;but, this was for a lawyer more interested
                    in ease of reaping.

                    I have done 133 line halftones on this machine.

                    MaiKätzchen
                     
                    Dum loquimur, fugerit invida Aetas:
                    Carpe diem!
                    quam minimum credula postero!

                    Horace
                    Odes Book I



                    From: Scott Rubel <scott@...>
                    To: PPLetterpress@yahoogroups.com
                    Sent: Sat, October 22, 2011 5:07:41 PM
                    Subject: Re: [PPLetterpress] Laser Engraved Photopolymer Plates



                    The website days it goes to 1200 dpi. If the coordinate tracking is accurate as it cuts, that should render pretty good six point type.

                    It is hard to tell the quality of the laser, but I think I will ask them for a sample of steel backed polymer. I wonder how that works without the steel acting like a mirror.

                    These laser beams can be unbelievable thin, if they are high quality. I work at a place where we make giant cameras for giant telescopes, and we order custom "slit masks" which are large sheets of aluminum with thousands of precision placed cuts in them. The cuts aren't much thicker than a hair, and you would think the laser is just moving along a path and cutting the slit, but in reality it cuts out the shape of the slit and almost microscopic blanks fall out of the metal every time a slit is cut. So if this Epilog Legend 36EXT machine is high quality, I would think six point type should work fine.

                    --Scott

                    On Oct 22, 2011, at 2:31 PM, Peter Fraterdeus wrote:



                    I'm interested in how well these desktop lasers can render type below 6 points.
                    We run a LOT of business cards, many of which were designed for mice, apparently ;-)

                    Not ready to get rid of my Interflex platemaker yet!

                    P

                    Peter Fraterdeus
                    Exquisite letterpress takes time™ 
                    tweet: @slowprint

                    IdeasWords : Idea Swords
                    Communication Strategy
                    Semiotx.com  @ideaswords

                    On 22 Oct 2011, at 2:40 PM, Silber MaiKätzchen wrote:



                    What number, thickness and brand plate are you 
                    using?

                    I use a Epilog Legend 36EXT with a 120W laser, I 
                    am using a plate now that I like that comes with 
                    a steel or poly backing. It takes me eight minutes 
                    to do a 6X9" plate from Cobalt, their AccuLaze in 
                    11 pt.

                    MaiKätzchen
                     
                    Dum loquimur, fugerit invida Aetas: 
                    Carpe diem! 
                    quam minimum credula postero!

                    Horace 
                    Odes Book I



                    From: Gerald Lange <Bieler@...>
                    To: PPLetterpress@yahoogroups.com
                    Sent: Fri, October 21, 2011 11:50:01 PM
                    Subject: [PPLetterpress] RE: Laser Engraved Photopolymer Plates

                    Of potential interest is this thread from Briar Press Discussions:

                    http://www.briarpress.org/27881

                    Gerald



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                  • Joe Lanich
                    Thank you for the compliment, you are very kind. Scanning precision or scan gap on a laser is the amount the laser head indexes in the Y axis per pass on
                    Message 9 of 29 , Oct 25, 2011
                    • 0 Attachment
                      Thank you for the compliment, you are very kind. 

                      "Scanning precision" or "scan gap" on a laser is the amount the laser head indexes in the Y axis per pass on the X axis. The lower the scan gap the more passes the engraving will be divided into. More passes equal more time. We run our laser at a scan gap of .04mm (0.0016") and the manufacturer refers to this 600DPI. If you do the math, 1" / 0.0016" = 625LPI. With laser beam diameter being around .003"-.005" I don't see any great benefit going above 625LPI for most work. At a scan gap of 1000LPI your plate engraving time would be 60% longer than 600LPI and you might not even be able to see the difference.  I am still experimenting though, so I am open to other opinions.

                      We use Illustrator to create all of our files and import them into the laser control program which then creates the code the laser needs to operate. 

                      CorelDraw? No hipster letterpress printer would be caught dead using CorelDraw! I kid! I'm sure it is a great program.

                      -Joe

                      On Tue, Oct 25, 2011 at 2:05 PM, Scott Rubel <scott@...> wrote:
                       

                      This is informative. You do some fun work.


                      I looked at the link and it seems like a wonderful machine, except for the "scanning precision" of 50-1000. I'm not sure what that means. Is that the same as maximum resolution? If so, I wonder why they would not want to take full advantage of what a laser is capable of.

                      In the compatible software category, it does not include Illustrator or InDesign. You said it likes vector files best, so do you make everything in CorelDraw (which I didn't even know was sill around)?

                      --Scot

                      On Oct 25, 2011, at 5:46 AM, Joe Lanich wrote:



                      Scott, 

                      You will have to excuse my adjectives. I try to remain humble because I know I am still young and I still have much to learn. I don't want to oversell anything on a mailing list created by a man that prints pieces such as this: http://www.flickr.com/photos/bielerpress/5288736711/

                      For the work we do (invites, coasters, greeting cards, etc) I would say this direct engrave polymer is excellent. You can find photos of our work here: http://www.laughingowlpress.com/work/. The photos on that page are not all inclusive to this direct engrave material. Some of the work was with conventional photopolymer, laser engravings of MDF and delrin, and type. Now we use the direct engrave polymer exclusively. Using the direct engrave process allows us to go from computer to plate in one step with minimal equipment investment. It has shortened our lead times and lowered our cost compared to when we had plates made offsite.  

                      The laser engraver we have is a 40watt Rabbit 6040. You can find it here: http://www.rabbitlaserusa.com/laser_RL6040.asp . You can use any engraver you wish. For this direct engrave polymer we run ours at 28% power, so you could even have a lower wattage of laser and still have success. In the end the machine you buy will affect both your quality of engraving and ease of use. My biggest gripe is the import control software for our laser is clunky, but it works. It likes vector files the most. 

                      The engraving does leave a slope on the engraving, you can see a picture of it on the briarpress.org thread about this material. 

                      Thank you for your questions. They greatly help with understanding the material. I look forward to more. 

                      -Joe







                    • Scott Rubel
                      That s a relief it takes Illustrator. I forgot to ask if you are using steel backed plates. The rest of this is good information. I m starting to want one.
                      Message 10 of 29 , Oct 25, 2011
                      • 0 Attachment
                        That's a relief it takes Illustrator. I forgot to ask if you are using steel backed plates.

                        The rest of this is good information. I'm starting to want one.

                        --Scott

                        On Oct 25, 2011, at 7:10 PM, Joe Lanich wrote:

                        Thank you for the compliment, you are very kind. 

                        "Scanning precision" or "scan gap" on a laser is the amount the laser head indexes in the Y axis per pass on the X axis. The lower the scan gap the more passes the engraving will be divided into. More passes equal more time. We run our laser at a scan gap of .04mm (0.0016") and the manufacturer refers to this 600DPI. If you do the math, 1" / 0.0016" = 625LPI. With laser beam diameter being around .003"-.005" I don't see any great benefit going above 625LPI for most work. At a scan gap of 1000LPI your plate engraving time would be 60% longer than 600LPI and you might not even be able to see the difference.  I am still experimenting though, so I am open to other opinions.

                        We use Illustrator to create all of our files and import them into the laser control program which then creates the code the laser needs to operate. 

                        CorelDraw? No hipster letterpress printer would be caught dead using CorelDraw! I kid! I'm sure it is a great program.

                        -Joe



                      • Harold Kyle
                        When you say LPI do you mean DPI? LPI refers to the screen resolution of a halftone. http://desktoppub.about.com/cs/intermediate/a/measure_lpi.htm As Gerald
                        Message 11 of 29 , Oct 25, 2011
                        • 0 Attachment
                          When you say LPI do you mean DPI? LPI refers to the screen resolution of a halftone. http://desktoppub.about.com/cs/intermediate/a/measure_lpi.htm

                          As Gerald mentioned earlier, most plates are made from films output at 2400 or 2540 DPI. 

                          Harold

                          On Tue, Oct 25, 2011 at 10:10 PM, Joe Lanich <ppp@...> wrote:
                           

                          Thank you for the compliment, you are very kind. 


                          "Scanning precision" or "scan gap" on a laser is the amount the laser head indexes in the Y axis per pass on the X axis. The lower the scan gap the more passes the engraving will be divided into. More passes equal more time. We run our laser at a scan gap of .04mm (0.0016") and the manufacturer refers to this 600DPI. If you do the math, 1" / 0.0016" = 625LPI. With laser beam diameter being around .003"-.005" I don't see any great benefit going above 625LPI for most work. At a scan gap of 1000LPI your plate engraving time would be 60% longer than 600LPI and you might not even be able to see the difference.  I am still experimenting though, so I am open to other opinions.

                          We use Illustrator to create all of our files and import them into the laser control program which then creates the code the laser needs to operate. 

                          CorelDraw? No hipster letterpress printer would be caught dead using CorelDraw! I kid! I'm sure it is a great program.

                          -Joe

                          On Tue, Oct 25, 2011 at 2:05 PM, Scott Rubel <scott@...> wrote:
                           

                          This is informative. You do some fun work.


                          I looked at the link and it seems like a wonderful machine, except for the "scanning precision" of 50-1000. I'm not sure what that means. Is that the same as maximum resolution? If so, I wonder why they would not want to take full advantage of what a laser is capable of.

                          In the compatible software category, it does not include Illustrator or InDesign. You said it likes vector files best, so do you make everything in CorelDraw (which I didn't even know was sill around)?

                          --Scot

                          On Oct 25, 2011, at 5:46 AM, Joe Lanich wrote:



                          Scott, 

                          You will have to excuse my adjectives. I try to remain humble because I know I am still young and I still have much to learn. I don't want to oversell anything on a mailing list created by a man that prints pieces such as this: http://www.flickr.com/photos/bielerpress/5288736711/

                          For the work we do (invites, coasters, greeting cards, etc) I would say this direct engrave polymer is excellent. You can find photos of our work here: http://www.laughingowlpress.com/work/. The photos on that page are not all inclusive to this direct engrave material. Some of the work was with conventional photopolymer, laser engravings of MDF and delrin, and type. Now we use the direct engrave polymer exclusively. Using the direct engrave process allows us to go from computer to plate in one step with minimal equipment investment. It has shortened our lead times and lowered our cost compared to when we had plates made offsite.  

                          The laser engraver we have is a 40watt Rabbit 6040. You can find it here: http://www.rabbitlaserusa.com/laser_RL6040.asp . You can use any engraver you wish. For this direct engrave polymer we run ours at 28% power, so you could even have a lower wattage of laser and still have success. In the end the machine you buy will affect both your quality of engraving and ease of use. My biggest gripe is the import control software for our laser is clunky, but it works. It likes vector files the most. 

                          The engraving does leave a slope on the engraving, you can see a picture of it on the briarpress.org thread about this material. 

                          Thank you for your questions. They greatly help with understanding the material. I look forward to more. 

                          -Joe










                          --
                          ---
                          Boxcar Press
                          501 W. Fayette St. #222
                          Syracuse, NY  13204
                          www.boxcarpress.com
                        • Erik Desmyter
                          I have been working with CNC routers and that logic will be similar. Technically such machines move a tool (router or laser for example) in a 2-dimensional XY
                          Message 12 of 29 , Oct 26, 2011
                          • 0 Attachment
                            I have been working with CNC routers and that logic will be similar. Technically such machines move a tool (router or laser for example) in a 2-dimensional XY surface from one X1Y1point to another point X2Y2. Every straight vector in the software file will mean one such move (a circle will be many very small straight moves after each other).

                            One stepper motor takes care of the X-movement and at the same time another stepper motor takes care of the Y-movement. Technically the software can say for example to move with a straight line from (X1= 0.123 mm, Y1= 0.234 mm) to (X2= 0.548 mm; Y2= 0.965 mm) but often the machine cannot move with such a 0.001 mm accuracy and tolerance.

                            Stepper motors move in steps and "one step" can translate on a specific machine to for example a move of 0.040 mm/step in the X-axe or Y-axe and then they will claim that machine has an accuracy of 0.040 mm/step what then translates as 625 of these steps are needed to move the tool 1 inch in the X- or Y-direction.

                            If you would for example use such a machine to make only horizontal lines along the Y-direction then you could in theory make 625 of those lines per inch in the X-direction. First line at X= 0mm, second line at X= 0.040mm, third line at X= 0.080mm, etc...

                            Most routers & lasers however do not move with only horizontal lines (like an inkjet printer does) so you can't compare this with traditional screen or printer logic.

                            Best regards,
                            Erik


                            When you say LPI do you mean DPI? LPI refers to the screen resolution of a halftone. http://desktoppub.about.com/cs/intermediate/a/measure_lpi.htm

                            As Gerald mentioned earlier, most plates are made from films output at 2400 or 2540 DPI. 

                            Harold

                            On Tue, Oct 25, 2011 at 10:10 PM, Joe Lanich <ppp@...> wrote:
                             

                            Thank you for the compliment, you are very kind. 


                            "Scanning precision" or "scan gap" on a laser is the amount the laser head indexes in the Y axis per pass on the X axis. The lower the scan gap the more passes the engraving will be divided into. More passes equal more time. We run our laser at a scan gap of .04mm (0.0016") and the manufacturer refers to this 600DPI. If you do the math, 1" / 0.0016" = 625LPI. With laser beam diameter being around .003"-.005" I don't see any great benefit going above 625LPI for most work. At a scan gap of 1000LPI your plate engraving time would be 60% longer than 600LPI and you might not even be able to see the difference.  I am still experimenting though, so I am open to other opinions.

                            We use Illustrator to create all of our files and import them into the laser control program which then creates the code the laser needs to operate. 

                            CorelDraw? No hipster letterpress printer would be caught dead using CorelDraw! I kid! I'm sure it is a great program.

                            -Joe

                            On Tue, Oct 25, 2011 at 2:05 PM, Scott Rubel <scott@...> wrote:
                             

                            This is informative. You do some fun work.


                            I looked at the link and it seems like a wonderful machine, except for the "scanning precision" of 50-1000. I'm not sure what that means. Is that the same as maximum resolution? If so, I wonder why they would not want to take full advantage of what a laser is capable of.

                            In the compatible software category, it does not include Illustrator or InDesign. You said it likes vector files best, so do you make everything in CorelDraw (which I didn't even know was sill around)?

                            --Scot

                            On Oct 25, 2011, at 5:46 AM, Joe Lanich wrote:



                            Scott, 

                            You will have to excuse my adjectives. I try to remain humble because I know I am still young and I still have much to learn. I don't want to oversell anything on a mailing list created by a man that prints pieces such as this: http://www.flickr.com/photos/bielerpress/5288736711/

                            For the work we do (invites, coasters, greeting cards, etc) I would say this direct engrave polymer is excellent. You can find photos of our work here: http://www.laughingowlpress.com/work/. The photos on that page are not all inclusive to this direct engrave material. Some of the work was with conventional photopolymer, laser engravings of MDF and delrin, and type. Now we use the direct engrave polymer exclusively. Using the direct engrave process allows us to go from computer to plate in one step with minimal equipment investment. It has shortened our lead times and lowered our cost compared to when we had plates made offsite.  

                            The laser engraver we have is a 40watt Rabbit 6040. You can find it here: http://www.rabbitlaserusa.com/laser_RL6040.asp . You can use any engraver you wish. For this direct engrave polymer we run ours at 28% power, so you could even have a lower wattage of laser and still have success. In the end the machine you buy will affect both your quality of engraving and ease of use. My biggest gripe is the import control software for our laser is clunky, but it works. It likes vector files the most. 

                            The engraving does leave a slope on the engraving, you can see a picture of it on the briarpress.org thread about this material. 

                            Thank you for your questions. They greatly help with understanding the material. I look forward to more. 

                            -Joe












                            -- 
                            ---
                            Boxcar Press
                            501 W. Fayette St. #222
                            Syracuse, NY  13204
                            www.boxcarpress.com



                          • Joe Lanich
                            Erik, great explanation. Perhaps the confusion is coming from me thinking in machinist terms on a printers mailing list. Allow me to further the confusion...
                            Message 13 of 29 , Oct 26, 2011
                            • 0 Attachment
                              Erik, great explanation. Perhaps the confusion is coming from me thinking in machinist terms on a printers mailing list. Allow me to further the confusion...
                              My next thought is on DPI. At a scan gap (or step) setting of .0016" on the X and Y axis I would have 625 points the machine can resolve to on the X axis and 625 points the machine can resolve to on the Y axis. If my logic is correct then 625 * 625 = 390,625 points that the machine can resolve to per square inch. How does this number equate to DPI? It is said that 2400DPI is camera ready art, does this mean I am engraving at a resolution greater than 2400 DPI? I realize that some of this will be washed out with the beam width of .003"-.005". 

                              Scott - The plates are plastic backed. The backer on them is thicker than a conventional PP plate, it is .02". I believe this gives the plate more stability for the heat of engraving and also provides a solid "bottom" to engrave to.  In the future I may look into metal backed plates as suggested by Gerald on the Briarpress discussion because it would be nice to use a magnetic base in the engraver to hold the plates. For now though, the plastic backed plates with two sided tape work well.

                              On Wed, Oct 26, 2011 at 7:26 AM, Erik Desmyter <erik.desmyter@...> wrote:
                               

                              I have been working with CNC routers and that logic will be similar. Technically such machines move a tool (router or laser for example) in a 2-dimensional XY surface from one X1Y1point to another point X2Y2. Every straight vector in the software file will mean one such move (a circle will be many very small straight moves after each other).

                              One stepper motor takes care of the X-movement and at the same time another stepper motor takes care of the Y-movement. Technically the software can say for example to move with a straight line from (X1= 0.123 mm, Y1= 0.234 mm) to (X2= 0.548 mm; Y2= 0.965 mm) but often the machine cannot move with such a 0.001 mm accuracy and tolerance.

                              Stepper motors move in steps and "one step" can translate on a specific machine to for example a move of 0.040 mm/step in the X-axe or Y-axe and then they will claim that machine has an accuracy of 0.040 mm/step what then translates as 625 of these steps are needed to move the tool 1 inch in the X- or Y-direction.

                              If you would for example use such a machine to make only horizontal lines along the Y-direction then you could in theory make 625 of those lines per inch in the X-direction. First line at X= 0mm, second line at X= 0.040mm, third line at X= 0.080mm, etc...

                              Most routers & lasers however do not move with only horizontal lines (like an inkjet printer does) so you can't compare this with traditional screen or printer logic.

                              Best regards,
                              Erik


                              When you say LPI do you mean DPI? LPI refers to the screen resolution of a halftone. http://desktoppub.about.com/cs/intermediate/a/measure_lpi.htm

                              As Gerald mentioned earlier, most plates are made from films output at 2400 or 2540 DPI. 

                              Harold

                              On Tue, Oct 25, 2011 at 10:10 PM, Joe Lanich <ppp@...> wrote:
                               

                              Thank you for the compliment, you are very kind. 


                              "Scanning precision" or "scan gap" on a laser is the amount the laser head indexes in the Y axis per pass on the X axis. The lower the scan gap the more passes the engraving will be divided into. More passes equal more time. We run our laser at a scan gap of .04mm (0.0016") and the manufacturer refers to this 600DPI. If you do the math, 1" / 0.0016" = 625LPI. With laser beam diameter being around .003"-.005" I don't see any great benefit going above 625LPI for most work. At a scan gap of 1000LPI your plate engraving time would be 60% longer than 600LPI and you might not even be able to see the difference.  I am still experimenting though, so I am open to other opinions.

                              We use Illustrator to create all of our files and import them into the laser control program which then creates the code the laser needs to operate. 

                              CorelDraw? No hipster letterpress printer would be caught dead using CorelDraw! I kid! I'm sure it is a great program.

                              -Joe

                              On Tue, Oct 25, 2011 at 2:05 PM, Scott Rubel <scott@...> wrote:
                               

                              This is informative. You do some fun work.


                              I looked at the link and it seems like a wonderful machine, except for the "scanning precision" of 50-1000. I'm not sure what that means. Is that the same as maximum resolution? If so, I wonder why they would not want to take full advantage of what a laser is capable of.

                              In the compatible software category, it does not include Illustrator or InDesign. You said it likes vector files best, so do you make everything in CorelDraw (which I didn't even know was sill around)?

                              --Scot

                              On Oct 25, 2011, at 5:46 AM, Joe Lanich wrote:



                              Scott, 

                              You will have to excuse my adjectives. I try to remain humble because I know I am still young and I still have much to learn. I don't want to oversell anything on a mailing list created by a man that prints pieces such as this: http://www.flickr.com/photos/bielerpress/5288736711/

                              For the work we do (invites, coasters, greeting cards, etc) I would say this direct engrave polymer is excellent. You can find photos of our work here: http://www.laughingowlpress.com/work/. The photos on that page are not all inclusive to this direct engrave material. Some of the work was with conventional photopolymer, laser engravings of MDF and delrin, and type. Now we use the direct engrave polymer exclusively. Using the direct engrave process allows us to go from computer to plate in one step with minimal equipment investment. It has shortened our lead times and lowered our cost compared to when we had plates made offsite.  

                              The laser engraver we have is a 40watt Rabbit 6040. You can find it here: http://www.rabbitlaserusa.com/laser_RL6040.asp . You can use any engraver you wish. For this direct engrave polymer we run ours at 28% power, so you could even have a lower wattage of laser and still have success. In the end the machine you buy will affect both your quality of engraving and ease of use. My biggest gripe is the import control software for our laser is clunky, but it works. It likes vector files the most. 

                              The engraving does leave a slope on the engraving, you can see a picture of it on the briarpress.org thread about this material. 

                              Thank you for your questions. They greatly help with understanding the material. I look forward to more. 

                              -Joe












                              -- 
                              ---
                              Boxcar Press
                              501 W. Fayette St. #222
                              Syracuse, NY  13204
                              www.boxcarpress.com




                            • Erik Desmyter
                              Joe, dpi is per inch in only one dimension so not per square inch . I guess that your laser beam width of 0.003 to 0.005 diameter will also result in some
                              Message 14 of 29 , Oct 26, 2011
                              • 0 Attachment
                                Joe,

                                dpi is "per inch" in only one dimension so not "per square inch". I guess that your laser beam width of 0.003" to 0.005" diameter will also result in some limitations when you have to cut away for example the sharp top of the triangle inside the letter A.

                                Best regards,
                                Erik



                                Erik, great explanation. Perhaps the confusion is coming from me thinking in machinist terms on a printers mailing list. Allow me to further the confusion...
                                My next thought is on DPI. At a scan gap (or step) setting of .0016" on the X and Y axis I would have 625 points the machine can resolve to on the X axis and 625 points the machine can resolve to on the Y axis. If my logic is correct then 625 * 625 = 390,625 points that the machine can resolve to per square inch. How does this number equate to DPI? It is said that 2400DPI is camera ready art, does this mean I am engraving at a resolution greater than 2400 DPI? I realize that some of this will be washed out with the beam width of .003"-.005". 

                                Scott - The plates are plastic backed. The backer on them is thicker than a conventional PP plate, it is .02". I believe this gives the plate more stability for the heat of engraving and also provides a solid "bottom" to engrave to.  In the future I may look into metal backed plates as suggested by Gerald on the Briarpress discussion because it would be nice to use a magnetic base in the engraver to hold the plates. For now though, the plastic backed plates with two sided tape work well.

                                On Wed, Oct 26, 2011 at 7:26 AM, Erik Desmyter <erik.desmyter@...> wrote:
                                 

                                I have been working with CNC routers and that logic will be similar. Technically such machines move a tool (router or laser for example) in a 2-dimensional XY surface from one X1Y1point to another point X2Y2. Every straight vector in the software file will mean one such move (a circle will be many very small straight moves after each other).

                                One stepper motor takes care of the X-movement and at the same time another stepper motor takes care of the Y-movement. Technically the software can say for example to move with a straight line from (X1= 0.123 mm, Y1= 0.234 mm) to (X2= 0.548 mm; Y2= 0.965 mm) but often the machine cannot move with such a 0.001 mm accuracy and tolerance.

                                Stepper motors move in steps and "one step" can translate on a specific machine to for example a move of 0.040 mm/step in the X-axe or Y-axe and then they will claim that machine has an accuracy of 0.040 mm/step what then translates as 625 of these steps are needed to move the tool 1 inch in the X- or Y-direction.

                                If you would for example use such a machine to make only horizontal lines along the Y-direction then you could in theory make 625 of those lines per inch in the X-direction. First line at X= 0mm, second line at X= 0.040mm, third line at X= 0.080mm, etc...

                                Most routers & lasers however do not move with only horizontal lines (like an inkjet printer does) so you can't compare this with traditional screen or printer logic.

                                Best regards,
                                Erik


                                When you say LPI do you mean DPI? LPI refers to the screen resolution of a halftone. http://desktoppub.about.com/cs/intermediate/a/measure_lpi.htm

                                As Gerald mentioned earlier, most plates are made from films output at 2400 or 2540 DPI. 

                                Harold

                                On Tue, Oct 25, 2011 at 10:10 PM, Joe Lanich <ppp@...> wrote:
                                 

                                Thank you for the compliment, you are very kind. 


                                "Scanning precision" or "scan gap" on a laser is the amount the laser head indexes in the Y axis per pass on the X axis. The lower the scan gap the more passes the engraving will be divided into. More passes equal more time. We run our laser at a scan gap of .04mm (0.0016") and the manufacturer refers to this 600DPI. If you do the math, 1" / 0.0016" = 625LPI. With laser beam diameter being around .003"-.005" I don't see any great benefit going above 625LPI for most work. At a scan gap of 1000LPI your plate engraving time would be 60% longer than 600LPI and you might not even be able to see the difference.  I am still experimenting though, so I am open to other opinions.

                                We use Illustrator to create all of our files and import them into the laser control program which then creates the code the laser needs to operate. 

                                CorelDraw? No hipster letterpress printer would be caught dead using CorelDraw! I kid! I'm sure it is a great program.

                                -Joe

                                On Tue, Oct 25, 2011 at 2:05 PM, Scott Rubel <scott@...> wrote:
                                 

                                This is informative. You do some fun work.


                                I looked at the link and it seems like a wonderful machine, except for the "scanning precision" of 50-1000. I'm not sure what that means. Is that the same as maximum resolution? If so, I wonder why they would not want to take full advantage of what a laser is capable of.

                                In the compatible software category, it does not include Illustrator or InDesign. You said it likes vector files best, so do you make everything in CorelDraw (which I didn't even know was sill around)?

                                --Scot

                                On Oct 25, 2011, at 5:46 AM, Joe Lanich wrote:



                                Scott, 

                                You will have to excuse my adjectives. I try to remain humble because I know I am still young and I still have much to learn. I don't want to oversell anything on a mailing list created by a man that prints pieces such as this: http://www.flickr.com/photos/bielerpress/5288736711/

                                For the work we do (invites, coasters, greeting cards, etc) I would say this direct engrave polymer is excellent. You can find photos of our work here: http://www.laughingowlpress.com/work/. The photos on that page are not all inclusive to this direct engrave material. Some of the work was with conventional photopolymer, laser engravings of MDF and delrin, and type. Now we use the direct engrave polymer exclusively. Using the direct engrave process allows us to go from computer to plate in one step with minimal equipment investment. It has shortened our lead times and lowered our cost compared to when we had plates made offsite.  

                                The laser engraver we have is a 40watt Rabbit 6040. You can find it here: http://www.rabbitlaserusa.com/laser_RL6040.asp . You can use any engraver you wish. For this direct engrave polymer we run ours at 28% power, so you could even have a lower wattage of laser and still have success. In the end the machine you buy will affect both your quality of engraving and ease of use. My biggest gripe is the import control software for our laser is clunky, but it works. It likes vector files the most. 

                                The engraving does leave a slope on the engraving, you can see a picture of it on the briarpress.org thread about this material. 

                                Thank you for your questions. They greatly help with understanding the material. I look forward to more. 

                                -Joe












                                -- 
                                ---
                                Boxcar Press
                                501 W. Fayette St. #222
                                Syracuse, NY  13204
                                www.boxcarpress.com








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