This is Cuprous Oxide and it must be precipitated or it is "fogged". The precipitation of a Cuprous salt from water with a peptizing agent forms a non-foggy Cuprous Oxide crystal that can be coated and developed.
Sulfuric Acid is not excreted by the human body in any way, nor is it normally produced!
It is not gelatin. I used a stable polymer but forget the structure. Last time I did this work was in the 70s. Gelatin is used later on for coating, but not for PPTN. The gelatin is destroyed by the acid and base used.