The Emulsion Authority List provides data values for the Emulsion element.
scope note: Gelatin emulsions have been used since the 1880s to produce dry plate negatives, Eastman paper negatives, Eastman gelatin film, cellulose nitrate film, cellulose acetate film, and polyester film. Gelatin emulsions have also been used to process Silver Gelatin Prints, which can be created on either "developing out" paper or "printing out" paper. By 1910, silver gelatin developing-out paper prints were standard. Silver gelatin emulsions are used in the Polaroid process. Color prints are created by processes that use chemically-dyed gelatin emulsions.
source: Administration of Photographic Collections