U of S | Mailing List Archive | alt-photo-process-l | Re: finer aquatint screen revisited

Re: finer aquatint screen revisited



Nothing new yet Susan. The last screen I mentioned seems to be working fine. I pinged the sales rep yesterday to see when their Scitex imagesetter was due for a PM next to see if that eliminated the unsightly water marks, which don't appear to read, but which concern me nonetheless.

I'll try calling him again today.

Thanks!
Jon



SusanV wrote:
Jon,

Any new news about the finer screens?  I'd love to try one.

Susan

On 4/22/07, Jon Lybrook <jon@terabear.com> wrote:
Hi all you Poly Plate People!

Just finished evaluating some tests I did using a 2540 dpi random dot
screen make from a Scitex imagesetter.  The results are very good --
better than the 1800 dpi screen made from the Agfa Imagesetter.  There
is a washout pattern visible in the screen, probably due to exhausted
chemistry, but the good new is it doesn't seem to read in the tests.  I
think the exposure unit burns right through that stuff and so the KM73
plate, for whatever reason, doesn't see it.  End result seems to show
better tonality than 1800 dpi with no noticeable increase in degradation
of the plate.  Haven't tested exactly how many prints I can get out of
one plate yet however.  Under the 1800 dpi screen a client of mine said
he was able to get 25 before the plate started showing signs of wear,
but I don't know what his workflow is either.  There could be other
things he could do differently to increase plate longevity.

I'm going to have the vendor send me another test after the imagesetter
has gotten a PM and chemistry change to see if the pattern goes away.
I'm working on a number of leads on vendors who are willing to do this
kind of output on a regular basis for us.  Anyone interested in it could
certainly find someone with a Scitex imagesetter and get their own
screens made - Just tell them you want a positive, 80% density, 2540
dpi, random dot screen.  I'll check, but I don't think there are any
more parameters than that.

With Susan's recent success with PDN and the KM73 plates, I predict that
approach in conjunction with employing a finer random dot screen is
going to give an amazing boost to the current standard of tonal quality
and smoothness possible with this process.

Best wishes,
Jon