Jason,

Thanks for trying to resuscitate this forum! I’d give a lot for a return to the days of good, meaty discussion.

When I first started emulsion making I read veraciously. I came across a number of references to using ammonium halides in a role as silver solvent. I incorporated that as a given in my subsequent recipe development. The addition of ammonium bromide to the salts in gaslight paper (i.e. Azo-type) eliminates any little “pepper grains” in the emulsion. (That's not the only method, but it's by far the easiest.)

The only reference I can lay my hands on immediately is good, old Baker (I’ve got his book memorized!) From page 78 of the 1st edition (1941): “A small quantity of ammonia should always be present in either the salts or the first silver solutions, otherwise clots or agglomerates of precipitates may be formed, which will cause black spots on development without exposure…”