An orotone or goldtone is a photographic print made from a negative (digital or silver). A glass plate is first coated with a silver gelatine emulsion. After exposure and development, the back of the plate is coated with a gold or silver pigment varnish or gold leaf. Because they are printed on glass, the images are fragile and the process is very long and painstaking. This technique was developed by Edward S. Curtis (1868-1952) in his antrophological work on the North American Indian.
"Ordinary photographic prints lack depth or, more accurately, translucence. In orotones, they are full of life and sparkle like an opal."