Polyvinyl-alcohol is another colloid that can be used for making relief images I guess.

Here are 2 formulas, one for ammonium dichromate and the other for p-Diazo-diphenyl-amine-formaldehyde.

http://www.poval.jp/english/poval/appli/ap_6-4.html

Just came across this and wanted to also see if anything's going on with diazo sensitizing lately...?