Re: Plate making
- I do the hand washout thing with very good results--it took a little
practice but it's really not hard. I think the main thing besides adequate
exposure under a tight negative is to be patient and gentle.
The unexposed polymer will almost just wash itself off the plate under warm
water--just don't get impatient and try to brush too hard--that is when fine
detail will start to break up.
I can't really say that I typically use such plate for 6 pt. type,
though--mostly just line artwork. I usually set or cast all type in
metal--much cheaper that way (at least in terms of material cost).
Just my .02,
- 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
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
Now It's Up To You Publications
157 S. Logan, Denver CO 80209
- On 1/6/02 5:28 PM, "Katie Harper" <knharper@...> wrote:
> This may beYou are certainly correct that trial and error is expensive. I think that
> 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.
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
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.
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Fine Printing and Binding ~ Digital Letterpress Supplies
640 Fellows Avenue ~ Syracuse, NY 13210
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