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Re: [PPLetterpress] correcting ink spread

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  • Gerald Lange
    ... Erik In the context of the above, I would be removing existing instances of ink spread from a previously letterpress printed image. A number of different
    Message 1 of 13 , Aug 13, 2002
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      Erik Desmyter wrote:
      >
      > .....I need to be able to work with the image, drop out page
      > material (foxing, show-through, etc), correct ink spread....
      > So I need to work in grayscale.
      >
      > What steps do you do in Adobe Photoshop to correct ink spread?
      > Erik
      >

      Erik

      In the context of the above, I would be removing existing instances of ink
      spread from a previously letterpress printed image. A number of different
      filters can be used in different ways to do this. It is somewhat dependent
      upon the image. But to do this, as I've suggested a couple of times now
      (ahem), you need to work on the image in grayscale mode. If you do this in
      bitmap mode all you have at your disposal is the eraser tool. A dangerous
      weapon in that you cannot otherwise alter the existent image and still
      maintain historical accuracy.

      But before I generate any image that is going to be printed letterpress I will
      also modify the image output to counteract the expected effect of impression
      and accumulating ink gain (spread). The same as I would recommend for type.
      Basically you need to thin the image a tad. Again, the sequence of filters
      would depend upon the image. I could go through the sequencing here but I'm
      not sure it would help all that much, since it is a variable call. Bit
      intuitive. Basic use of the selection tool and the ubiquitous Photoshop
      filers. Nothing fancy required, but very time consuming. I do not screw around
      with the output channels as alteration there is less controllable. Too quick
      and dirty for my tastes.

      If you'd like to send me a PDF or jpeg of your image (but um, a bit reduced in
      rez as my email will probably choke on it!), I can possibly make some
      recommendations as to how I might proceed with it.

      All best

      Gerald
    • Gerald Lange
      ... Well, I m tempted on this one Katie. But... specifically, the colorful and not so colorful stains left on the sheet from mold and mildew. Though it often
      Message 2 of 13 , Aug 13, 2002
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        Katie Harper wrote:
        >
        > Gerald: What is "foxing?" s'il vous plait?
        >

        Well, I'm tempted on this one Katie.

        But... specifically, the colorful and not so colorful stains left on the sheet
        from mold and mildew. Though it often also refers to any discoration caused as
        a result of over-exposure to dampness and/or humidity. Can't remember if rust
        stains are also considerated as such or if they have their own special term.

        Gerald
      • Erik Desmyter
        .....I need to be able to work with the image, drop out page material (foxing, show-through, etc), correct ink spread.... So I need to work in grayscale. What
        Message 3 of 13 , Aug 13, 2002
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          .....I need to be able to work with the image, drop out page
          material (foxing, show-through, etc), correct ink spread....
          So I need to work in grayscale.


          What steps do you do in Adobe Photoshop to correct ink spread?
          Erik
        • Katie Harper
          Gerald: What is foxing? s il vous plait? Katie Harper Ars Brevis Press Cincinnati, OH 513-233-9588 http://www.arsbrevispress.com
          Message 4 of 13 , Aug 13, 2002
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            Gerald: What is "foxing?" s'il vous plait?


            Katie Harper
            Ars Brevis Press
            Cincinnati, OH
            513-233-9588
            http://www.arsbrevispress.com





            > From: Gerald Lange <bieler@...>

            >>
            >> .....I need to be able to work with the image, drop out page
            >> material (foxing, show-through, etc), correct ink spread....
            >> So I need to work in grayscale.
          • Peter Fraterdeus
            ... Erik I d use a levels adjustment layer... since the scanner records gray levels for points that are mid-way between the imaging elements, (on the edge of a
            Message 5 of 13 , Aug 13, 2002
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              At 2:08 PM +0000 2002-08-13, Gerald Lange wrote:
              >Erik Desmyter wrote:
              >>
              >> .....I need to be able to work with the image, drop out page
              >> material (foxing, show-through, etc), correct ink spread....
              >> So I need to work in grayscale.
              >>
              >> What steps do you do in Adobe Photoshop to correct ink spread?
              > > Erik
              >>
              >...

              Erik

              I'd use a levels adjustment layer...
              since the scanner records gray levels for points that are mid-way between the imaging elements, (on the edge of a line or curve, for instance, in line art) the layers adjustment allows you to play with the line width of your scan, opening or closing details and highlights...

              Used with fuzzy layer masks, you get plenty of control over these details.

              PF

              --
              -
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              Peter Fraterdeus http://www.midsummernightstamps.com
              www.semiotx.com Magical Images from the Moon's Garden!

              Whatever happened to the War Against Injustice and Poverty!
              End Terrorism? End Poverty!
            • bielerpr
              ... Hi Mark The unsharp mask is quite useful, in some situations, maybe most, but it most usually is one of the last filters you would use in a sequence as it
              Message 6 of 13 , Aug 14, 2002
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                > Gerald and Erik,
                >
                > This may sound a bit too easy, but I have found that unsharp masking
                > (usually twice at 500%) is the one filter that really seems to open up a
                > line image for good letterpress printing.
                >
                > are there any other filters that you can recommend ?
                >
                > thanks,
                > Mark.
                >

                Hi Mark

                The unsharp mask is quite useful, in some situations, maybe most, but
                it most usually is one of the last filters you would use in a
                sequence as it is clearly a "demarcation" filter. The movement is
                from "fuzz" to clarity. Introduce clarity too soon and you have to
                retrace your steps.

                Problem with most of these filters is they really need to be used in
                combination and seqsuence. Lot of experimentation at first, and every
                image has its own requirements. More art than science if you are
                trying to get it right. Can't come up with a consistent recipe.

                But if unsharp seems to be working, keep doing it. 500% is a huge
                movement though, isn't it? I'm a bit too cautious perhaps. Maybe I
                just don't trust in this stuff enough.

                Gerald
              • Gerald Lange
                ... Mark There are three control parameters for the unsharp mask filter. What are your exact settings for each? Gerald
                Message 7 of 13 , Aug 14, 2002
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                  Mark Attwood wrote:
                  >
                  > Gerald,
                  >
                  > I find that for some odd reason that unsharp masking at such high levels of
                  > 500% seems to open up the areas that are likely to fill in on the press and
                  > at the same time strengthen light details that are likely to drop out, as
                  > sort of fix-both-problems at the same time solution. I haven't found any
                  > other filters that seem to help much though.
                  >
                  > Mark Attwood
                  >
                  Mark

                  There are three control parameters for the unsharp mask filter. What are your
                  exact settings for each?

                  Gerald
                • Mark Attwood
                  Gerald and Erik, This may sound a bit too easy, but I have found that unsharp masking (usually twice at 500%) is the one filter that really seems to open up a
                  Message 8 of 13 , Aug 14, 2002
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                    Gerald and Erik,

                    This may sound a bit too easy, but I have found that unsharp masking
                    (usually twice at 500%) is the one filter that really seems to open up a
                    line image for good letterpress printing.

                    are there any other filters that you can recommend ?

                    thanks,
                    Mark.


                    Mark Attwood

                    The Artists' Press
                    Box 623
                    Newtown
                    2113
                    South Africa

                    Tel. +27 11 836 5474
                    fax. +27 11 836 6858
                    mark@...
                  • Mark Attwood
                    Gerald, I find that for some odd reason that unsharp masking at such high levels of 500% seems to open up the areas that are likely to fill in on the press and
                    Message 9 of 13 , Aug 14, 2002
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                      Gerald,

                      I find that for some odd reason that unsharp masking at such high levels of
                      500% seems to open up the areas that are likely to fill in on the press and
                      at the same time strengthen light details that are likely to drop out, as
                      sort of fix-both-problems at the same time solution. I haven't found any
                      other filters that seem to help much though.


                      Mark Attwood

                      The Artists' Press
                      Box 623
                      Newtown
                      2113
                      South Africa

                      Tel. +27 11 836 5474
                      fax. +27 11 836 6858
                      mark@...


                      ----------
                      >From: "bielerpr" <bieler@...>
                      >To: PPLetterpress@yahoogroups.com
                      >Subject: [PPLetterpress] Re: correcting ink spread
                      >Date: Wed, Aug 14, 2002, 8:13 am
                      >

                      >
                      >> Gerald and Erik,
                      >>
                      >> This may sound a bit too easy, but I have found that unsharp masking
                      >> (usually twice at 500%) is the one filter that really seems to open up a
                      >> line image for good letterpress printing.
                      >>
                      >> are there any other filters that you can recommend ?
                      >>
                      >> thanks,
                      >> Mark.
                      >>
                      >
                      > Hi Mark
                      >
                      > The unsharp mask is quite useful, in some situations, maybe most, but
                      > it most usually is one of the last filters you would use in a
                      > sequence as it is clearly a "demarcation" filter. The movement is
                      > from "fuzz" to clarity. Introduce clarity too soon and you have to
                      > retrace your steps.
                      >
                      > Problem with most of these filters is they really need to be used in
                      > combination and seqsuence. Lot of experimentation at first, and every
                      > image has its own requirements. More art than science if you are
                      > trying to get it right. Can't come up with a consistent recipe.
                      >
                      > But if unsharp seems to be working, keep doing it. 500% is a huge
                      > movement though, isn't it? I'm a bit too cautious perhaps. Maybe I
                      > just don't trust in this stuff enough.
                      >
                      > Gerald
                      >
                      >
                      >
                      >
                      >
                      > • To respond to a post or post a message to the membership:
                      > PPLetterpress@yahoogroups.com
                      > • Encountering problems? contact:
                      > PPLetterpress-owner@yahoogroups.com
                      > • To unsubscribe:
                      > PPLetterpress-unsubscribe@yahoogroups.com
                      >
                      > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                      >
                    • Michael Peich
                      ... Hey Gerry, (or should I say, Gerald?) It s been fascinating reading e-mails from this group, although the polymer plate discussions are way over my leaded
                      Message 10 of 13 , Aug 14, 2002
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                        on 8/14/02 1:13 AM, bielerpr at bieler@... wrote:

                        >
                        >> Gerald and Erik,
                        >>
                        >> This may sound a bit too easy, but I have found that unsharp masking
                        >> (usually twice at 500%) is the one filter that really seems to open up a
                        >> line image for good letterpress printing.
                        >>
                        >> are there any other filters that you can recommend ?
                        >>
                        >> thanks,
                        >> Mark.
                        >>
                        >
                        > Hi Mark
                        >
                        > The unsharp mask is quite useful, in some situations, maybe most, but
                        > it most usually is one of the last filters you would use in a
                        > sequence as it is clearly a "demarcation" filter. The movement is
                        > from "fuzz" to clarity. Introduce clarity too soon and you have to
                        > retrace your steps.
                        >
                        > Problem with most of these filters is they really need to be used in
                        > combination and seqsuence. Lot of experimentation at first, and every
                        > image has its own requirements. More art than science if you are
                        > trying to get it right. Can't come up with a consistent recipe.
                        >
                        > But if unsharp seems to be working, keep doing it. 500% is a huge
                        > movement though, isn't it? I'm a bit too cautious perhaps. Maybe I
                        > just don't trust in this stuff enough.
                        >
                        > Gerald
                        >
                        >
                        >
                        >
                        >
                        > • To respond to a post or post a message to the membership:
                        > PPLetterpress@yahoogroups.com
                        > • Encountering problems? contact:
                        > PPLetterpress-owner@yahoogroups.com
                        > • To unsubscribe:
                        > PPLetterpress-unsubscribe@yahoogroups.com
                        >
                        > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                        >
                        >


                        Hey Gerry, (or should I say, Gerald?)

                        It's been fascinating reading e-mails from this group, although the
                        polymer plate discussions are way over my leaded head. You've become the
                        guru for this stuff, and impressively knowledgeable.

                        One quick piece of business. I am a member of the APHA board of
                        directors and at our last meeting I agreed to contact you about your lapsed
                        membership. Since you were the individual who encouraged me to join APHA a
                        number of years ago, I want to encourage you to renew your membership. Lots
                        of good things are happening, and we need all the support we can muster. Do
                        it.

                        I suspect I'll see you next at Oak Knoll. Have a productive few last
                        gasp of summer, and early fall.

                        Cheers, Mike
                      • Erik Desmyter
                        ... 500%, radius about 1.2 pixels and threshold about 5. set the amount at 500 and then play with the radius, at some point you will quickly see you will get
                        Message 11 of 13 , Aug 15, 2002
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                          > As you say there is a bit more art than science but the usual is: Amount
                          500%, radius about 1.2 pixels and threshold about 5. set the amount at 500
                          and then play with the radius, at some point you will quickly see you will
                          get the optimal result.

                          If you go to our PPletterpress website
                          http://groups.yahoo.com/group/PPLetterpress/ and go for "Files" (at the left
                          side) and then under "How to" you will see 6 small files I have created as
                          an example. What I have done is I first made in Adobe photoshop a letter R
                          in Times New Roman at 12 points (R created in photoshop 2400ppi.TIF). This
                          file was then printed with a standard HP laserprinter 5L at 600dpi and this
                          printed document was then scanned at 600ppi, 1200ppi, 2400ppi in line art
                          and also 600ppi in grayscales.

                          I have also tried the above unsharp masking correction (500%, radius, 1.2
                          pixels, 5 threshold) on the grayscale scan (R scan grayscales 600ppi +
                          unsharp masking.PDF).

                          The goal should be to get back (after the scanning and the clean up) as
                          close as possible to the original creation. The printing with a laser
                          printer at 600dpi is losing a lot of quality but I think real letterpress
                          printing will have more quality loss with more ink spread, etc...

                          Please feel free to use one of the 4 scans and try to do some processing or
                          correction to get to a good result as close as possible to the original.

                          Erik
                        • Mark Attwood
                          Hi Gerald, As you say there is a bit more art than science but the usual is: Amount 500%, radius about 1.2 pixels and threshold about 5. set the amount at 500
                          Message 12 of 13 , Aug 15, 2002
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                            Hi Gerald,

                            As you say there is a bit more art than science but the usual is: Amount
                            500%, radius about 1.2 pixels and threshold about 5. set the amount at 500
                            and then play with the radius, at some point you will quickly see you will
                            get the optimal result. I don't know if this is the best way, just what I
                            have discovered is best for me. I would appreciate any feedback from others
                            in this regard.


                            Mark Attwood

                            The Artists' Press
                            Box 623
                            Newtown
                            2113
                            South Africa

                            Tel. +27 11 836 5474
                            fax. +27 11 836 6858
                            mark@...


                            ----------
                            >From: Gerald Lange <bieler@...>
                            >To: PPLetterpress@yahoogroups.com
                            >Subject: Re: [PPLetterpress] Re: correcting ink spread
                            >Date: Wed, Aug 14, 2002, 9:30 am
                            >

                            > Mark Attwood wrote:
                            >>
                            >> Gerald,
                            >>
                            >> I find that for some odd reason that unsharp masking at such high levels of
                            >> 500% seems to open up the areas that are likely to fill in on the press and
                            >> at the same time strengthen light details that are likely to drop out, as
                            >> sort of fix-both-problems at the same time solution. I haven't found any
                            >> other filters that seem to help much though.
                            >>
                            >> Mark Attwood
                            >>
                            > Mark
                            >
                            > There are three control parameters for the unsharp mask filter. What are your
                            > exact settings for each?
                            >
                            > Gerald
                            >
                            >
                            >
                            > ï To respond to a post or post a message to the membership:
                            > PPLetterpress@yahoogroups.com
                            > ï Encountering problems? contact:
                            > PPLetterpress-owner@yahoogroups.com
                            > ï To unsubscribe:
                            > PPLetterpress-unsubscribe@yahoogroups.com
                            >
                            > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
                            >
                          • Gerald Lange
                            Hi Gerald, As you say there is a bit more art than science but the usual is: Amount 500%, radius about 1.2 pixels and threshold about 5. set the amount at 500
                            Message 13 of 13 , Aug 15, 2002
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                              Hi Gerald,

                              As you say there is a bit more art than science
                              but the usual is: Amount
                              500%, radius about 1.2 pixels and threshold about
                              5. set the amount at 500
                              and then play with the radius, at some point you
                              will quickly see you will
                              get the optimal result. I don't know if this is
                              the best way, just what I
                              have discovered is best for me. I would
                              appreciate any feedback from others
                              in this regard.


                              Mark Attwood

                              The Artists' Press
                              Box 623
                              Newtown
                              2113
                              South Africa

                              Tel. +27 11 836 5474
                              fax. +27 11 836 6858
                              mark@...

                              Dear Mark

                              Thought I'd test this out with a something I would have found quite difficult.
                              I downloaded an image of one of Tycho's Brahe's astronomical instruments,
                              printed in the 16th century. This was a very colorful JPEG at 300 dpi. I
                              opened it in Photoshop, re-sampled to 600 dpi and converted it to a grayscale.
                              I ran your formula twice and converted the file to b/w bitmap while
                              re-sampling to 1200 dpi. I printed it out at 1200 dpi. Fell out of my chair.
                              Absolute clarity and as perfect a conversion of the blacks and whites as I
                              have ever seen. All in about five minutes of time!!!

                              You have found the Holy Grail my son. I get down on my knees to you.

                              All best

                              Gerald
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