Quote Originally Posted by Henry Carter View Post
Sounds like a PYRO based formulation such as PMK PYRO. The stain masks the grain and yields wonderful edge effects and hence high acceptance with films like HP5, and with PYRO you maintain good highlight detail without blowing out the highlights.
That should read 'high ACCUTANCE', and not 'acceptance' - gotta love automatic spell checkers!

PMK PYRO gives wonderful edge effects with high accutance films such as HP5, increasing perceived sharpness. The stain partly masks the grain but also acts as a hardener and reduces local infectious development and hence helps maintain highlight detail even with overexposure.

My lab divides the development into 2 baths to prevent exhaustion of the developer (for 16 minutes of development it is 2 baths at 8 min each).