Dry plates are photographic plates coated with a light-sensitive gelatin emulsion, introduced as an advancement over the earlier wet collodion process. Unlike wet plates, which had to be exposed and developed while still moist, dry plates could be prepared in advance, stored, and used later, making photography more convenient and flexible.
Dry plates revolutionized photography in the late 19th century by allowing photographers to work outdoors and carry pre-prepared plates, leading to faster exposure times and greater portability. They were a key step toward modern film and greatly contributed to the expansion of amateur and professional photography.