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

Re: solarplate wedgies

Again, using Kreene in place of glass solved that problem long ago for me. Matte plastic in place of glass = no newton rings. Just taped it using gaffer's tape around the perimeter of the frame and wedged strips of foamcore in the slots where the glass used to be to increase contact. It wasn't a walk in the part to remove the glass from my vacuum frame, and the pressure decreased quite a bit, but I didn't need all that much as it turns out: 12-15 psi seem to be plenty given an adequate drawdown time (now possible due to Keith's suggestion that I dry my OHP for 15-20 minutes prior to exposing -- Thanks again Keith!). No patches from above nor below.
Mostly I've been doing plates for clients' work which I don't have permission to post, old family photos with fading issues, or abstract works that wouldn't be good as demos. I'll post a more standard print for review and critique this week.


Christina Z. Anderson wrote:
You mean to tell me that even with a vacuum frame you are still having this as a major problem? Will it never end? I can feel your pain. There have been several times I have felt like giving up. Or, at least, sticking to busy images with no appreciable large areas of dark.

Let me add another idea to your arsenal of why the dots: I notice the dots are very prevalent at some ratios of aquatint exposure/positive. I don't have a definitive answer on this yet, and may never, but someone out there does. I am guessing that a hefty aquatint exposure is necessary to prevent them, too.

Also, remember the tidbit I shared a while ago about tissue paper between glass and pictorico (and baby powder). Perhaps there is a tissue paper out there that is thin enough not to print texture into your image, perhaps a vellum or whatnot. Might be worth a shot.

Since this stuff is used for computer chips it has GOT to have the potential to be accurate.

Mind you, I have, by my current calculations, gone through about 50 plates this semester....the benefit that I have learned a LOT about solarplate, but every turn I find there is another variable to test.

----- Original Message ----- From: "SusanV" <susanvoss3@gmail.com>
To: <alt-photo-process-l@usask.ca>
Sent: Tuesday, April 03, 2007 8:15 AM
Subject: Re: solarplate wedgies

On 4/2/07, Christina Z. Anderson <zphoto@montana.net> wrote:

where are you Susan, Jon, Keith?  Spring

Hi Chris,

Yeah, last week I had a sick kid and was full-timing as Dr Mom, and
now this week is Spring break with husband AND kid home, so studio
time has been limited.  Thanks for all the work you've done on those
ratio tests... It supports what we've already noticed to a degree, but
doing the side-by-side comparisons gives us solid information.

I'm still troubled with small irregularities of tone, which I have
finally come to realize are being caused by Newton's rings forming
both between the glass and the top surface of the imagesetter aquatint
film, and the glass and the OHP.  (When vacuumed in my NuArc bed)
Have talked it over with Sandy King and others at the the HybridPhoto
site and I think we have decided that a piece of Mylar, sprayed with a
light coating of clear matte spray, placed under the glass, will stop
the rings.  I'm off today to get some mylar and will try to test that
later.  That would be a major breakthrough for me, because I have not
been able to get any smooth tones, which also was a big problem with
trying to calibrate and get a curve via PDN.

gotta run for now..


gravure blog at www.susanvossgravures.blogspot.com
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