[alt-photo] Ammonium Caseinate vs. Sodium Caseinate

[Don Bryant]

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