Platinum paper is created by hand coating an acid-free paper with liquid platinum. The image is then contact printed onto the paper, creating a print that is the same size as the negative. The image becomes embedded in the paper, creating a three-dimensional depth specific to platinum prints. The delicate, rich 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 paper surface, while silver lies in a gelatin or albumen emulsion that coats the paper. As a result, since no gelatin emulsion is used, the final platinum image is absolutely matte with a deposit of platinum absorbed slightly into the paper.
Platinum prints are among the most permanent objects; platinum metals are more stable than gold.