noun
: any of various processes involving the use of gelatin: as
a. : a photographic process in which gelatin is used as the dispersing vehicle for the sensitive silver salts
b. : a printing process for reproducing pictures or drawings based upon the action of light on a bichromated gelatin film — compare aquatone , carbon process
c. : a method of producing facsimile copies of a written or drawn original with a pad of gelatin (as in a hectograph)