diffusion transfer process
n.A photographic process in which a print or transparency is developed while in contact with the negative, the image-forming material migrating from the negative through a thin layer of liquid.
NotesDeveloped in 1939 as a means to create rapid copies of documents. The process was later adapted for instant print cameras, such as Polaroid. Black-and-white images typically use silver halide as the image-forming material. Color photographs use dyes. The negative is typically disposed of after development, although Polaroid did make products (Type 51 and Type 105) that could produce a print and a negative that could be fixed and preserved.