Quote Originally Posted by R Shaffer View Post
Would the pyro formula I have come across in several places be a colloidal developer? I could not decide if the GP-2 or pyro developer would give me the best chance of success.
I assume you mean pyro + ammonia. Yes, since ammonia is an AgX solvent that would be a colloidal (or solution-physical) developer. The problem involved with is ammonia evaporation, which makes the solvent action of this developer very unreliable.