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Re: [PPLetterpress] Re: Plate making

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  • typetom@aol.com
    edinman@earthlink.net writes:
    Message 1 of 8 , Jan 6, 2002
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      edinman@... writes:
      <<I think the main thing besides adequate exposure under a tight negative is
      to be patient and gentle.... just don't get impatient and try to brush too
      hard--that is when fine detail will start to break up. >>

      I would add to this perhaps some refinement. Too much patience also can
      result in loss of serifs and details. How so? As the plate is soaked and
      washed, the unexposed parts absorb water and dissolve. This can occur under
      the hardened surface of exposed lines, so that the serif or thin line may
      lift off and be brushed away. I think it's not so much that the brush is
      damaging the surface image but that it is separating it from softer material
      below. So, fine lines benefit from slight over exposure, which allows more of
      the polymer to harden down the shoulders below the surface of the image. And
      similarly, fine lines would benefit from somewhat faster washout time, thus
      not allowing the supporting material to absorb so much water, but leaving the
      surface image better attached. So the success in preserving a delicate image
      is not just dependent on delicate brushing -- in fact it may help to brush a
      bit more aggressively, as odd as that seems. These factors can be felt by
      considering differences in hand-brushing a small versus a large plate. Using
      a small brush, it takes longer to work over the whole surface of a larger
      plate, so the larger plate takes longer to wash out. The result is that,
      while small plates may easily come out fine, larger plates may develop broken
      lines. A quicker washout may help. A parallel answer might be to halt the
      washout a bit earlier, before all the unexposed material has been cleaned
      away (and then trust the drying and the second exposure to reduce and harden
      that material).

      One thing I have found very useful is to keep an eye on the clock. If I have
      been gentle and patient but the plate isn't clean after about 10 minutes (in
      my experience, with the small brush and water temp I use) then I know it's
      probably time to stop anyhow. For me, it has been hard to stop cleaning --
      just as it is difficult for me to leave an irregular pile of freshly printed
      sheets as they sit rather than jog them straight. Naturally compulsive about
      straightening and finishing details, I guess. I've had to discipline my self.
      Watching the clock has made a difference.

      It seems there are several complex factors at work, and analysis of these
      things may produce contradictory conclusions about what's best to do. I am
      still puzzled how these various decisions can be made in the machine washout
      process. And it may be that the success of the machine process suggests to me
      that exposure time and washing time may be more important than the delicate
      touch. But mostly, I think, no one of my conclusions is the whole answer, and
      surely a gentle and patient touch must be a goal and a process for us all.

      Best wishes, Tom

      Tom Parson
      Now It's Up To You Publications
      157 S. Logan, Denver CO 80209
      (303) 777-8951
    • Harold Kyle
      ... You are certainly correct that trial and error is expensive. I think that the cost of the plate material should give any novice second thoughts about
      Message 2 of 8 , Jan 7, 2002
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        On 1/6/02 5:28 PM, "Katie Harper" <knharper@...> wrote:
        > This may be
        > because they need consistent, reliable results and it's cheaper and easier
        > in the long run to order plates rather that go through the trial and error
        > experimentation required to get good results themselves.

        You are certainly correct that trial and error is expensive. I think that
        the cost of the plate material should give any novice second thoughts about
        diving into the hand washing of plates.

        That said, I purchased a machine-washout platemaker after years of "trial
        and error" and consistent success with hand-washout. The volume of work in
        my shop convinced me because the commercial units are efficient and save
        precious time.

        Although I was pleased with my results while hand-washing (and didn't expect
        any improvement was possible), the results from the machine washout are
        superior. This came as quite a surprise. With eighteen 40W bulbs I'm getting
        much more even exposure than the eight 20W I used to use (now there are no
        light corners or banding). The evenness of the brush pressure and repeatable
        functions of the new platemaker mean sharper detail and noticeably crisper

        Larger (and, needless to say, more expensive) plates are particularly
        improved, because I don't need to submerge an 11x17 plate for fifteen
        minutes of scrubbing with a 4x8 brush. Remember that the adhesive which
        holds the polymer on the backing eventually dissolves in water--small
        details are the first to go when washout times increase.

        Hand-washing often works on medium to small-size plates, but a machine will
        always do a superior job and can process the biggest plates just as well as
        the smallest plates.

        Harold Kyle

        ~ ~ ~ ~ ~ ~
        Boxcar Press
        Fine Printing and Binding ~ Digital Letterpress Supplies
        640 Fellows Avenue ~ Syracuse, NY 13210
        ~ ~ ~ ~ ~ ~
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