[alt-photo] Re: Ammonium Caseinate vs. Sodium Caseinate

[Peter Friedrichsen]

While the ammonium caseinate exposes faster than gum, so does sodium 
caseinate; there must be another mechanism at work. I do admit that I 
have not compared the ammonium vs sodium, but only in reference to 
gum's exposure time and it is always less as you already know.

Peter Friedrichsen


At 07:33 PM 04/15/2011, you wrote:
>Hello Everyone,
>
>I've been quietly reading along through the exchange of e-mails trying to
>deduce what is required to make my own casein prints.
>
>So far I've made my first batch of ammonium caseinate (about 1 liter of
>liquid am. Caseinate preserved with thymol) using E.J. Theisen's
>instructions published on the internet. The liquid is about 48 hours old and
>still has a strong ammonia odor since it is stored in a capped Mason/Atlas
>canning jar. I assume one of the reasons (or maybe the primary reason) that
>Am. Cas. is so much faster than gum is because of the ammonia. As I recall,
>the treatment of gum emulsions to ammonia fumes or ad-ins caused a big speed
>jump for the gum coating. I've never tried this but I assume it has been
>documented as being true. Didn't David Scopic, Judy Siegel and perhaps
>others verify this?
>
>Tonight I will make another batch of casein and let it dry to produce a
>quantity of dry powder with thymol used as a preservative.
>
>Also, this weekend, I will attempt to make my own sodium caseinate using the
>formula published earlier by Alberto.
>
>My first test will be using E.J. Theisen's working formula using DS Grey
>Graphite printed on pre-shrunk Lenox sized with Gamblin PVA, 1:1 and
>pre-shrunk FAEW gelatin sized and hardened with glut. If I can find the pig.
>in my stash I may also try some Venetian/Indian Red.
>
>The tests will be made with a step wedge and in camera negative. Once I have
>a feel for the materials/process I will derive my tri-color curves (assuming
>all goes successfully).
>
>Now having stated all of that Chris made the following post RE: Sodium
>Caseinate:
>
>
> >
>1.14.81 Wrote this to Ross, Sam, Albert
>10g sod casein pdr
>150cc water
>60 drops glycerol
>4 drops photoflo
>12 drops 50% thymol
>then 2.3.81 mixed 15g in 150cc
>printed this 1.5-3mn
> >
>
>Does anyone understand what is indicated by the ratio or entry ... 'then
>2.3.81 mixed 15g in 150cc' ?
>
>I get part of that but not the 2.3.81. Is that a ratio or a date?
>
>Thanks,
>
>Don Bryant
>
>
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