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

[Christina Anderson]

Don
Can't wait until you test casein. Let us know your a) speed and b) whether you find it shorter in scale than gum.
1.14.81 is the date. 
Enos died in 83, so hence the 80s date.
He dated every recipe and experiment...
From what I remember, ammonia was used in gum printing to slow down the process, not speed it up in what I have read (lemon juice added speed which I think was just what Marek said in that it is a dichromate reducer or whatever the term was). I think casein is faster for different reasons, not least of which is the thinness of the layer
In fact, in some recipes as long as a dichromated colloid is full of ammonia and stlll in liquid state it is hardly sensitive but once it is coated on paper, the ammonia evaporates, it becomes sensitive. Or so I've read. This was also the basis of Kwik Print and perhaps the Selectacolor presensitized liquid coating.
Chris
Christina Z. Anderson
christinaZanderson.com

On Apr 15, 2011, at 5:33 PM, Don Bryant 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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