Antracotypia (Resinotype) is very old alternative photographic technique invented by Rodolfo Namias (1867-1938), who adapted and enhanced the well known powder process (Garner and Salmon 1958). Every photographer slightly modify the process and so do I.
Basic principle is based on ability of gelatin (when sensitized by kalcium dichromate or the other sensitizer and exposed to UV light) to selectively absorb pigment according to how much was exposed to UV light.
Antracotypia on plastic board covered by metal leaves. Original pigment print.