U of S | Mailing List Archive | alt-photo-process-l | Re: photopolymer

Re: photopolymer

Hi Keith,

I tried working with the Welden screen and tested it for several months in conjunction with various finer line and stochastic screens, so I'm quite familiar with it. It works fine, of course, as I'm sure your work and Susan's latest prints will attest. The basic difference between the finer one I use and Dan's/Elizabeth's is that the pattern with theirs is visible to the naked eye. Mine just looks like a dark grey translucent screen. I'd guestimate theirs to be somewhere on the order of 150-200 dpi compared to the 1800-2540 dpi screens I've been using. The inkjet positive of course is the defining factor, and so having aquatint dots larger than the image dots is the main reason why I moved away from it. Once an area of the plate has been burned in with a 'white dot', no further definition of tone is possible in that area, thus, more contrast. Finer dots mean contact is even more of a critical factor, however. The standard screen is more forgiving in that regard.

I spoke with the graphics firm I've been working with in Denver on Friday. The finer stochastic screens I've asked them to make work well, but there was still this issue of a washout pattern (which doesn't seem to read on the plate) which I'm hoping gets addressed when they do the next PM/chemistry change on their SciTex imagesetter (for aesthetic reasons if nothing else). After the PM (regardless of the aesthetics), I'll send you, Susan and Chris samples to play with and will post contact info on the company. I've been told to get back in touch with them in 2-3 weeks regarding the PM. Their screens are working well, as I said, but are not as fine looking under the lupe as the ones I used to get from Peter Ellzey Copy Graphics in Santa Fe. Not sure it matters that much since my tests show there's little difference to the human eye between super-fine (2540 dpi) and fine (1800 dpi) once the stuff has been translated to poly plate and back to paper anyway -- curves adjust tone as needed in both cases and create very similar results in the end. I've recently found and been in touch with the elusive Mr. Peter Ellzey, formerly of Copy Graphics, who has some ideas about how to reproduce the screens he used to make for me with their Agfa imagesetter. There was some confusion both with him and Copy Graphics regarding the use of Icefields software to create the 1800 dpi screens for me. I kept all the tests we tried and looked at them yesterday. Icefields is definitely NOT what we were using, assuming they were labeled correctly. Icefields screens were more coarse and with a pattern more visible to the naked eye. Peter has kindly agreed to talk with Copy Graphics and try some stuff next week for me. Very happy to hear he's doing well, teaching and working in film production, but still with an avid interest in this stuff. I'll keep you posted on these developments as well.


Keith Taylor wrote:

Once the Kreene arrives on Monday I will remove the glass and have a similar setup to you. The Mylar was just a temporary replacement. I've removed the glass once before and had it crack on me, so I know what you mean by intimidating!

I use Dan Welson's screen which is surprisingly fine compared to Elizabeth Dove's. I'm curious to know how fine it is compared to yours. I should send you a piece to compare the two. I have a 5K lamp used in conjunction with an integrator. Before I pulled the frame apart last week and changed the foam pad and started using the Mylar, my exposures were very close to yours. Since the changes however, my exposures have increased, about +20% which isn't a problem. I'm waiting for the Kreene to arrive before I make any more tests though. I'll let you know more next week!


On May 5, 2007, at 4:06 AM, Jon Lybrook wrote:

Hi Keith,

Glad to hear the mylar solved the contact problems for you.
I've actually removed the glass entirely from my contact frame and just have Kreene stretched across it. I thought of trying taping it across the glass, but Harold at Box Car seemed to feel the added effect of the glass + kreene wouldn't be as crisp...or something. In any case, I'm happy with the way it's been working, though removing the glass was a little intimidating at the time.

Also, I was wondering what image/screen/wattage you're using for exposures just out of curiosity...