[alt-photo] Re: casein
zphoto at montana.net
Sat Apr 23 14:22:46 GMT 2011
LOL Alberto, this is GREAT. Here is, therefore, one pigment that is "incompatible" with casein--in stock, that is.
I have stock solutions of about 10 pigmented caseins mixed up and when this happened it made me worry about all the rest, too. But so far, so good. I have mixed some iron based earths, though...red iron oxides, yellow ochres...we'll see how those fare.
Christina Z. Anderson
On Apr 23, 2011, at 3:49 AM, Alberto Novo wrote:
>> Continuing my casein exploration. Today I went to use my nickel azo yellow stock solution and here is what it looked like: http://christinaanderson.visualserver.com/Text_page.cfm?pID=2076 not a problem with thalo and magenta (yet). Interesting.
> "It combines readily with bases forming compounds, and resembles albumen by
> being precipitated by the metallic salts, and forming with them two
> combinations, namely, one of casein and the acid, and another of casein and
> the metallic oxide."
> (quoted from Richard's post)
> This is the answer to your question: the interaction between nichel and casein. The same should happen with copper, manganese, chromium and other metallic pigments, like verdigris, manganese violet, raw and burnt umber, viridian green, hematite, Mars black and other iron-based earths, etc.
> But I think that they require some time to react with casein, like in your experience.
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