Platinum prints, also called platinotypes, are photographic prints made by a monochrome imaging process. The platinum tones range from warm black, to reddish brown, to expanded mid-tone grays that are unobtainable in silver prints. Unlike the silver print process, platinum lies on the surface of the paper surface, versus inside of a gelatin or albumen emulsion. This results in a final image that is absolute matte, with a deposit of platinum and palladium, absorbed slightly into the paper.
Platinum prints are the most durable of all printing processes. The platinum group metals are very stable against chemical reactions that may degrade the print—even more stable than gold. It is estimated that a platinum image, properly made, can last thousands of years.
The reflections in a platinum print are much more diffused, compared to glossy prints which have a high specularity. Platinum prints provide delicate but large tonal ranges. The darkest possible tones in the prints will be lighter than silver based prints, because it is coated on 100% rag paper.