[alt-photo] Re: casein cont...

[Matti Koskinen]

On 24.10.2011 19:05, Christina Anderson wrote:
> one other thing matti i am using only a 10% potassium dichromate, even less therefore than my usual 15% ammonium dichromate for a 6 minute exposure with gum.
>
> do you mean "no detail" meaning that the highlights lose detail when you brush? or the print in general is low contrast?
> Christina Z. Anderson
> christinaZanderson.com
>
> On Oct 24, 2011, at 9:04 AM, Matti Koskinen wrote:
>
the print shows only very dark or pure white parts. I just mixed curd+1% 
ammonia, and in unblinkingeye-site recipe it'll take 24 hours to all the 
curd to dissolve. Laura says she mixes the curd and ammonia with an 
electric blender and uses the stuff immediately. I tried with Sienna 
colour a print and even one hour exposure revealed only slight image. 
Looks like the casein goes bad the older it is, as yesterday the 
exposure times were shorter. The Sienna print was coated only by 
brushing and it didn't show the white lines as using black colour. Also 
Laura uses ammonium dichromate and I potassium. Could there be a 
reaction different than mixing amm di with casein, which contains 
ammonia as pot di with ammonia?

-matti