[Alt-photo] casein and Ferrari red

[Christina Anderson]

Dear All,
I have been working on a body of casein prints. Today I decided to use some PR254, that beautiful Ferrari Red (Daniel Smith Pyrrol Red, Da Vinci Red, Maimeri Sandal Red, M.Graham pyrrol red, Rembrandt permanent red deep, Schmincke scarlet, Sennelier red, Winsor red are some brand names). Works great with gum for a brilliant lipstick red.

I mixed it up with my casein and it was instant curdle/coagulation of the casein! No problem at all with the usual colors, but with the metal salts as has been discussed on the list you can work with them but stock solutions will lump up in a brief time into insoluble chunks so I never mix stock casein anymore once I learned that lesson. However, with nickel azo yellow, for instance, one of my favorite yellows that lumps up, I can still use it if I mix it up right at time of use. Same with red iron oxide.

But PR 254 is diketo pyrrollo-pyrole. Don't have any idea why that would make this happen instantly. Does anyone have a guess why this pigment causes instant coaglulation and precipitation of the casein??? Is it just an acidity thing or is it a metallic salt? It precipitated the casein into squishy curds. Never seen this happen so rapidly before...

Any other casein printers experience colors that coagulate, or want to pull out their PR254 and see this happen? If you have, what colors?
Chris 


Christina Z. Anderson
christinaZanderson.com