RE: types of casein

On Fri, 14 Nov 2003, Keith Gerling wrote:
>
> I mix up gloy the same as I do gum: One part colloid to two parts saturated
> Potassium Dichromate. Illinois well water. Same old brush and development
> techniques we all use. I should mention, though, that I recently switched
> from Dan Smith to Varn gum and found that they work identically. I seem to
> recall that you had no luck with Varn, sooooo, I guess maybe I'm lucky, or
> your not. ;-)

My trial of the Varn gum was specifically with lamp black because I'd had
trouble with it and Dave Rose said it worked fine with his gum. I used a
different black for the tests (this was two years ago, PLEASE don't ask me
to name that black) and the varn didn't work the most, others worked well,
including Daniel Smith -- tho theirs is different every year, and their
"premier" gum is VERY different from their plain lithographers $18/gallon
gum. (You didn't say which one you used --Tho maybe all 3 are the same in
Illinois well water???)

I realize the varn must work well wherever, but more tests got put on hold
(like Mae West said, so many tests, so little time). One interesting
thing, tho, the Varn label says not good after 6 months !!!! I expect to
use a given gum for years. Don't know what that was about... but will get
back to the issue if I live long enough. Meanwhile, I also put some Varn
in the freezer to test at future date.

> What IS gloy, anyway? Could it be plain old Gum Arabic? Looks like gum.

It is, at least according to Mike Ware, PVA -- polyvinyl acetate.. but
with additives for color, odor, texture, consistency, etc. (He didn't
mention flavor.) It's also a particular kind of PVA, which I'll recognize
the name of if you say it. Mike did a bunch of experiments with it -- I
have some of his step tests on file. He got about 5 or so steps, which
was good enough, but they weren't even... big jump at the top, which is
bad. He planned to continue testing, but I gather other priorities claimed
him.

Ware, however, was the one warned against using proprietary materials,
whether Photographer's Formulary "gum arabic" or Henkel gloy, down through
the list of other mixes or substances sold by company name rather than
formula or ingredients, as we saw recently when Photographer's Formulary
changed their gum arabic. I think we could all name similar experiences.
Gloy is evidently reasonably stable so far, but no guarantee. But if
you'd like to try some PVA experiments, I'll look up whatever info I have.

PS: Years ago, Stephen Livick swore by RGB gum, but then got on the
Bostick & Sullivan web site, and -- guess what?

PPS. Did you find a good colloid for coating glass? How about hard
gelatin ??? I know some folks do use that, tho it's NEVER easy.

Judy

> Sort of smells like gum. Tastes like gum. (says here on the bottle
> "complies with stringent EC child safety legislation", so I'm assuming its
> not toxic). Also says on the package "Original Gum". A while back, while
> trying to make the task of coating glass easier, I tested every colloid I
> could find: fish glue, casein, eggs, photoengraving glue, Equine Enteric
> Colloid, (funny the stuff you find at Farm and Fleet) and the two that
> behaved almost identically were Daniel Smith Gum and Gloy.
>
> Keith
>
> PS. Maybe its the water. Perhaps we should consider a trade...
>
>
>
> -----Original Message-----
> From: Judy Seigel [mailto:jseigel@panix.com]
> Sent: Friday, November 14, 2003 3:40 PM
> To: alt-photo-process-l@sask.usask.ca
> Cc: alt-photo-process-error@sask.usask.ca
> Subject: RE: types of casein
>
>
>
>
> On Fri, 14 Nov 2003, Keith Gerling wrote:
>
> > Yes. Totally the opposite here. I've found that gloy offers greater
> range
> > (more Stouffer steps) than gum. It is especially handy when one finds
> > themselves with a very thin negative. Alas, it is not available where I
> > live, or it would likely be my colloid of choice.
>
>
> That is astonishing. Do you have any idea why? Maybe there's some other
> way of doing it,, or could be the other ingredients? Maybe the water?
> Can you summarize your technique? I have a tad of gloy left & would try
> it.
>
> J.
>
Received on Sat Nov 15 15:27:07 2003