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Re: [PPLetterpress] Re: resolution

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  • Iohannes Daubmannus
    ... Gerald, thank you, it s just I need. But I m not sure... Can fine line size be smaller than isolated dot size? E.g. it tech specs of Toyobo Printight
    Message 1 of 15 , Sep 1, 2008
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      > on the best of plates,
      > fine lines accurately at .0015"
      > and isolated dots .0075" in diameter.

      Gerald, thank you, it's just I need.

      But I'm not sure...
      Can fine line size be smaller than isolated dot size?
      E.g. it tech specs of Toyobo Printight plates shown
      lines 0.1 mm (.004"), dots 0.02 mm (0.0008")

      Anyway if I make a test chart with stroke patterns from 0.01 mm (.2
      pt, .0004") to 0.5 mm (.02"), I'll see the real resolution on my plate
      and on my press. Am I right?
    • Gerald Lange
      Iohannes This is from a Toyobo Printight promo, not a technical sheet: Halftone resolution: 150 lpi Min. isolated dot: .0075 Min. isolated line: .0015 Real
      Message 2 of 15 , Sep 1, 2008
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        Iohannes

        This is from a Toyobo Printight promo, not a technical sheet:

        Halftone resolution: 150 lpi
        Min. isolated dot: .0075
        Min. isolated line: .0015

        Real resolution would be a bit of a misnomer but yes, certainly, test it
        out, and let us know your findings.

        Note that you will experience gain at the film negative stage, you will
        experience gain related to increased "printing pressure," and you will
        experience gain as the result of increasing ink film coverage. So there
        are a lot of variables that can throw your readings off.

        I have a number of technical test reports from Toyobo and the gain
        revealed from those is surprising high. Anything you can do at the
        prepress stage to counter this is your best option.

        Gerald
        http://BielerPress.blogspot.com

        Iohannes Daubmannus wrote:
        >> on the best of plates,
        >> fine lines accurately at .0015"
        >> and isolated dots .0075" in diameter.
        >>
        >
        > Gerald, thank you, it's just I need.
        >
        > But I'm not sure...
        > Can fine line size be smaller than isolated dot size?
        > E.g. it tech specs of Toyobo Printight plates shown
        > lines 0.1 mm (.004"), dots 0.02 mm (0.0008")
        >
        > Anyway if I make a test chart with stroke patterns from 0.01 mm (.2
        > pt, .0004") to 0.5 mm (.02"), I'll see the real resolution on my plate
        > and on my press. Am I right?
        >
        > ------------------------------------
        >
        >
      • Scott Rubel
        Whatever anyone says about resolution, my real world test was this. I scanned some illustrations of William Blake s fine line illustrations from Night
        Message 3 of 15 , Sep 1, 2008
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          Whatever anyone says about resolution, my real world test was this.

          I scanned some illustrations of William Blake's fine line
          illustrations from "Night Thoughts" and had polymer plates made and
          printed them on my C&P. I doubt that anyone could tell the difference
          between my reproduction and the Dover reproduction.

          That's enough information for me.

          --Scott Rubel

          On Sep 1, 2008, at 9:58 AM, Gerald Lange wrote:

          > Iohannes
          >
          > This is from a Toyobo Printight promo, not a technical sheet:
          >
          > Halftone resolution: 150 lpi
          > Min. isolated dot: .0075
          > Min. isolated line: .0015
          >
          > Real resolution would be a bit of a misnomer but yes, certainly,
          > test it
          > out, and let us know your findings.
          >
          > Note that you will experience gain at the film negative stage, you
          > will
          > experience gain related to increased "printing pressure," and you will
          > experience gain as the result of increasing ink film coverage. So
          > there
          > are a lot of variables that can throw your readings off.
          >
          > I have a number of technical test reports from Toyobo and the gain
          > revealed from those is surprising high. Anything you can do at the
          > prepress stage to counter this is your best option.
          >
          > Gerald
          > http://BielerPress.blogspot.com
          >
          > Iohannes Daubmannus wrote:
          >>> on the best of plates,
          >>> fine lines accurately at .0015"
          >>> and isolated dots .0075" in diameter.
          >>>
          >>
          >> Gerald, thank you, it's just I need.
          >>
          >> But I'm not sure...
          >> Can fine line size be smaller than isolated dot size?
          >> E.g. it tech specs of Toyobo Printight plates shown
          >> lines 0.1 mm (.004"), dots 0.02 mm (0.0008")
          >>
          >> Anyway if I make a test chart with stroke patterns from 0.01 mm (.2
          >> pt, .0004") to 0.5 mm (.02"), I'll see the real resolution on my
          >> plate
          >> and on my press. Am I right?
          >>
          >> ------------------------------------
          >>
          >>
          >
          >
          > ------------------------------------
          >
          > Yahoo! Groups Links
          >
          >
          >
        • Gerald Lange
          Iohannes The relief structure of photopolymer is unlike cast metal type and unlike photomechanical chemical etching. The longer the exposure latitude, the
          Message 4 of 15 , Sep 1, 2008
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            Iohannes

            The relief structure of photopolymer is unlike cast metal type and
            unlike photomechanical chemical etching.

            The longer the exposure latitude, the shallower the relief between
            surface imaging. Isolated elements, dots, lines, would thus have less
            structural support. But an isolated line would have better support
            than an isolated dot.

            I have put some images up in the photo section here
            Photos>Bieler Press
            that show microphotography of halftone plates at 150lpi. Note the
            variance in slope and relief based on different exposure latitude.

            Gerald
            http://BielerPress.blogspot.com

            >
            > But I'm not sure...
            > Can fine line size be smaller than isolated dot size?
            > E.g. it tech specs of Toyobo Printight plates shown
            > lines 0.1 mm (.004"), dots 0.02 mm (0.0008")
            >
            >
          • Iohannes Daubmannus
            Gerald, thanks for your explanation! ... Now I thought: is a common resolution test with stroke patterns (like 1951 USAF
            Message 5 of 15 , Sep 2, 2008
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              Gerald, thanks for your explanation!

              > Isolated elements

              Now I thought: is a common resolution test with stroke patterns (like 1951 USAF
              http://en.wikipedia.org/wiki/1951_USAF_Resolution_Test_Chart) suitable
              to determine minimum size of _isolated_ objects?..
              I'll add lines and dots with triple thickness distance between.
            • Iohannes Daubmannus
              please, take a look at my chart for the test: http://www.bjorn.kiev.ua/letterpress/res_test.pdf values (widths and dots diameters) shown in postscript points.
              Message 6 of 15 , Sep 2, 2008
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                please, take a look at my chart for the test:
                http://www.bjorn.kiev.ua/letterpress/res_test.pdf
                values (widths and dots' diameters) shown in postscript points.
              • Nicolas Goosen
                Very nice! I was just reminded of the Resometer chart. Considering that the Resometer target is nearly $400 I d have to say that your chart rocks! -Nicolas
                Message 7 of 15 , Sep 2, 2008
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                  Very nice!

                  I was just reminded of the 'Resometer' chart. Considering that the
                  Resometer target is nearly $400 I'd have to say that your chart rocks!

                  -Nicolas

                  > please, take a look at my chart for the test:
                  > http://www.bjorn.kiev.ua/letterpress/res_test.pdf
                  > values (widths and dots' diameters) shown in postscript points.
                  >
                • Gerald Lange
                  Iohannes This should work. I recall that BASF recommended printing a ruler in regard to stretch on cylinder mounted plates (just to ensure the math was
                  Message 8 of 15 , Sep 2, 2008
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                    Iohannes

                    This should work. I recall that BASF recommended printing a ruler in
                    regard to stretch on cylinder mounted plates (just to ensure the math
                    was correct). So you are on a proven track.

                    Gerald
                    http://BielerPress.blogspot.com

                    Iohannes Daubmannus wrote:
                    > please, take a look at my chart for the test:
                    > http://www.bjorn.kiev.ua/letterpress/res_test.pdf
                    > values (widths and dots' diameters) shown in postscript points.
                    >
                    > ------------------------------------
                    >
                    >
                    >
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