[alt-photo] Re: casein history

[Christina Anderson]

Peter,
Do you think there is a difference when using sodium carbonate vs. ammonia, since ammonia evaporates when coated?
Chris

Christina Z. Anderson
christinaZanderson.com

On Jul 13, 2012, at 9:25 PM, Peter Friedrichsen wrote:

> Marek,
> 
> From what I understand, the dichromates shift to chromates as they are made more alkaline (from your ammonia) and these salts are less reactive especially in the higher pH. That may explain the lessened dark reaction.
> 
> Peter Friedrichsen
> 
> 
> At 12:58 PM 13/07/2012, you wrote:
> 
>> Chris,I have not tried this approach yet, my bag of sawdust went missing. On the other hand I have been making some prints, mostly monochrome for about a year now. I have also made some prints from the one year old casein solutiojn, actually it was more then a year old. Works just fine. It is interesting that the first solution that I ever made turned to be the best recipe.Another interesting tidbit is that I have exposed and developed one day old paper checking for the signs of dark reaction and found none. There is one more piece from that batch that I will let sit for perhaps another day or two before exposing and developing. As to your other questions I read the PF article years back, but did not think of it much at the time (in terms of my own interest). I only got interested in it last year with the posts on the list.
>> 
>> >
>> > Also, Marek, you were talking about Fresson maybe containing casein. The amount of casein/gelatin I have come across is 10-30% casein to gelatin. Have you tried it yet?
>> >
>> > Chris
>> >
>> > Christina Z. Anderson
>> > christinaZanderson.com
>> >
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