From: Judy Seigel (email@example.com)
Date: 04/25/00-08:24:02 PM Z
On Tue, 25 Apr 2000 Smieglitz@aol.com wrote:
> ... I now believe based on years of experience and testing a seemingly
> infinite number of permutations in materials, that the quartz halogen, metal
> halide lamps, and the sun are much, much, much, much better for gum printing
> than the UV tubes. Several tests after the one I scanned also indicate this
> to be the case. I don't want to keep testing and speculating. My brain
> hurts. I want to move on and use my eyes now. I want to print some images.
Joe, I agree about the pain in the brain from testing, and clearly you've
done more than your share.... But it seems from here that what you've
proved is that quartz halogen (whatever they are) prints better for your
negative, paper, size, pigment, and esthetic combination than the BL
bulbs, not necessarily for someone else's. Since you didn't use a 21-step
this is little to go on besides "that's how Smieglitz makes a Smieglitz."
Which is to say, so far no objective or quantitative data or info.
Also, I gather from today's messages on the topic, the tests were done
with one coat of yellow. I take it however that your finished print is
several coats, tho whether in process (CMK) or other colors, you don't
say. Have you actually finished prints by QH or are these the
preliminaries? (In my experience, different colors print differently &
subsequent coats can "curve" differently from the first.)
> I won't be printing gum with UV tubes again.
> In a message dated 04/25/2000 17:47:59, firstname.lastname@example.org wrote:
> I remember from your tests of several months ago that perhaps there
> was a clearing issue. The BL vs. Halogen light sources in your tests
> are certainly printing differently, but I still wonder if it is more
> than just a speed issue. Did you try different lengths of exposure?
> Did you try clearing the BL prints longer? Perhaps the different
> light source affects the clearing rate (pure speculation)? I seem to
> remember you mentioned a 30 minute clearing bath. My prints sometimes
> don't even start to clear within 30 minutes. Not that I would wish an
> 8 hour clearing time on anyone, but it works for me and my prints do
> clear given enough time (yes, Judy, even with Joe's rabbit skin glue
> size which I have been using because it clears better than others).
> >Just a thought. Assume a layer of particles. Light striking straight
> >would expose less just beneath the particle than a diffused source
> >could angle around and expose under it.
> This may have something to do with it also, particularly since you
> used a yellow pigment, which should tend to absorb more of the
> blue-ultraviolet waves than other pigments. The diffused source would
> tend to cut in under the particles more, as Judy said. I'll also
> second what Judy said about the time lag. I've coated two sheets at
> once and exposed one up to 48 hours later with only a barely
> perceptible decrease in clearing of the highlights (granted it was
> cool weather and typical low Rocky Mountain humidity).
> >Halogen lamps appear to print cleaner, with better separation and
> >contrast with respect to the gum emulsion.
> Odd, it seems that most of us are going for less contrast (longer
> range) in a gum print. Or was this from a half-tone negative?
This archive was generated by hypermail 2b29 : 06/13/00-03:09:50 PM Z CST