Photopolymer plates are made by Toyobo Printight in Japan. The plates are=
=20
called KM 95R and KM 75R. The different numbers mean different sizes, one=
=20
is for A3 and other for A2. I tink they come in packages of 20 plates,=20
so it might get little expensive to just give them a try alone.In Finland=
=20
they are imported by Papyrus OY, But probably for some other purposes than=
=20
photogravyre. Also needed is some continuous tone films, we used Agfa gevar=
ex=20
GO 230p, and some graphic film, which is more contrasty, in case you can't =
achieve=20
required density (1,5) you have to make support with that. normal paper=20
developers, e.g. kodak dektol 1+5. Use dark red safetylight.
The film + screen are then exposed in UV - light (wavelenght about=20
380nm). you also need a vacuum frame to ensure contact. The gravure=20
method shows its best qualities with highlights - the influence of the=20
screen diminishes. Also juicy details & tones are available in darker=20
areas, and achieving black is never a problem.
There is a safetysheet on top of the polymer plate, which has to be=20
removed before exposure. the exposured plate looks somewhat like a green
plastic hologram, very interesting indeed. The screen's optimal density=20
is 0,5. If the density is smaller, the plate will receive some extra=20
light and that will reduce contrast. he amount of time the screen is=20
exposed should be as short as possible (not too short!), because the=20
exposing of the screen forms a net to the plate, in which the ink then=20
stays like this:
=20
the ink sticks in these tiny holes =20
! ! ! ! ! ! !
V V V V V V V =20
This is the -> ----__------_-_---_-_----_---------_------- =20
plate -> ___________________________________________
If the exposure is too long, the holes get deeper and too much ink gets=20
inside the plate. If exposure is too short, the holes are not formed at=20
all, but corroded to large areas or sunked in -surfaces.
The plate has a steel reinforcement on its bsck. it is developed in plain=
=20
water in a minute, then scrubbed gently with your hand in water for=20
another minute. The areas which didn't get light are sunked and the=20
plate becomes a negative. (So from a negative you make a larger=20
positive film) The plate is dried and then hardened in sunlight or uv=20
-light for some time to harden the plate so that it can be used in a=20
press. Notice: don't bend the plate! it cracked quite easily. Don't=20
worry if it curls, the press will strenghten it quite easily :-)
I won't give details about the printing, it is very similar to what one=20
should do with copper-plates, and there are plenty of books, experts an=20
courses to that thing. (Try it, its fun!)
Hope this helped. If not, better come to study in Finland (or in=20
denmark, or Norway, this process is known in someplaces over there too.=20
Anyone from there? hur =E4r det med det h=E4r processet i Sverige?)
I'm sure this process will become more popular after a while,=20
astonishing prints easily, fun and safe to do What else do you want? Get=20
materials for free? ;-)
tomi knuutila tomknuu@silmu.cc.jyu.fi may the force be with you
v=E4in=F6nkatu 40 b 13 p.+358- 41- 645723 =20
40520 jyv=E4skyl=E4 =20
finland ps. elvis e-mailed me last sunday