Re: UV lights for gum

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From: Darryl Baird (dbaird@flint.umich.edu)
Date: 04/25/00-06:34:55 PM Z


I'll address each question separately...anybody bored with this hit the big
ol' delete key.

Judy Seigel wrote:

> On Tue, 25 Apr 2000, Darryl Baird wrote:
>
> > As a part of that first online class (kudos, Dick...great idea and
> > experience) I was a victim of the fluorescent failure. I'd used an
> > Edwards Engineering box successfully for some prints in V.D, cyanotype
> > (original and Ware formulas), platinum, and gum. Of all of these gum was
> > the worst.
> > During the Livick class, my test negative just died in all tests and
> > soon it became apparent the difference was the light source. Subsequent
> > testing by another classmate, Joe Smeigel, with quartz halogen lamps
> > produced promising results, but the metal halide lamps were clear
> > winners.
> >
> > So, is it contrast, point source, or UV wave length concentration...???
>
> As ever, generalisations about gum printing seem to beg for contradiction.
> Or let me say again that recently when my NuArc died, I went back to the
> BL bulbs and found they printed much better, easier. My thought is that
> they print gum somewhat flatter -- ie, longer scale -- which could be why.
> (Tho when I had the reflective foil under the fluorescent bulbs they
> printed worse, purely fuzzified.)

Yes, I wasn't aware of the actual nature of my question at the time, I was
indeed begging.

> But what is an "Edwards Engineering box" anyway? What kind of bulbs? (Maybe
> BLB?)

The fluorescent UV box marketed by B&S, with 20W GE BL bulbs.

> And what are your criteria for "clear winner"? 21-steps? One
> coat prints? depth of color? number of steps? Or....????

Yes. Yes. Yes. (in tri color, three coats) See answer one.

> I'm also wondering what kind of negatives you found the metal halide best
> with -- I'm doing continuous tone at this point -- haven't tried digital
> or half tone yet with the BL bulbs, but there seem to be very great
> differences in printing characteristics between the two types, which could
> also be a factor, even *the* factor. Multiple coat & single coat gum can
> benefit from different treatment, too -- or ....... ?????

The test was meant to be halftone, but I substituted a digital neg. which
match the criteria of the test (as above)

> Finally, if I may, one more question: Darryl, what is the footprint of
> your Violux? And bed size? (Well, I guess that's two questions -- sorry.)

The violux is something like 18" square lightsouce (MH bulb in a shuttered,
reflector housing), with integrator and heavy-duty fan assembly. I use a
Nuarc flatbed vacuum frame...I think about the same size as yours, 26 X 30".
The lightsource is suspended above the frame, hanging from the floor rafters
above. (I'm in the basement. approx. 800 square feet of workspace.

As to my motivation and belief the metal halide is the way to go, I simply
rely on Stephen Livick prints. I've never seen anything quite like them. Deep
rich color, sharp, contrasty, and large. One of my main reasons for turning
to alt-process was to produce tri color prints. My quest began back in the
early 80s with the dreaded Kwik-Print process. I was dissuaded from gum in
graduate school and had wished to try them again when B&S offered the class
with Stephen...I saw prints I wanted to make and I'll continue to pursue his
system until I know enough to decide for myself. Until that magical time, I'm
following his methods very closely -- paper, sizing technique, watercolor
brand, light source, etc.

As I'm embarking on a series for a show this summer, I should know soon
enough if this is pure folly or a dream realized. Anyway, it's my dream and I
had some cash. Synchronicity I'd call it.

--
Darryl Baird


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