Surfactant, hardner and dye
I am overwhelmed by my learning on this forum!
Regarding the coating process, what kind of surfactant should be added to the gelatin (not soap I presume). Also, the hardner, would it work if I spray chromic K sulphate (chrom alum I think it's called) on the emulsion after it was applied to the film? And finally, where can i buy panchromatic dyes? Many many thanks.
Try good old photo flo 200, or something similar. Lots on sale, as long as there are no dyes or odors added.
The hardener should be added to the emulsion before coating for best results and it will take at least 24 hours to harden.
Panchromatic dyes are very hard to get and very expensive, about $100 - $200 / gram. Minimum order is usually 1 gram. Also, pan emulsions are very hard to coat unless you use IR safelights.