COLLOTYPE
collotype, collotype printing, photogelatin process
(noun) a photomechanical printing process that uses a glass plate with a gelatin surface that carries the image to be reproduced; can be used with one or more colors
Source: WordNet® 3.1
Etymology
Noun
collotype (countable and uncountable, plural collotypes)
(uncountable) A dichromate-based photographic process formerly used for large-volume mechanical printing.
(countable) An image produced by this process.
Source: Wiktionary
Col"lo*type, n. [Gr. glue + -type.]
Definition: A photomechanical print made directly from a hardened film of
gelatin or other colloid; also, the process of making such prints.
According to one method, the film is sensitized with potassium
dichromate and exposed to light under a reversed negative. After the
dichromate has been washed out, the film is soaked in glycerin and
water. As this treatment causes swelling in those parts of the film
which have been acted on by light, a plate results from which
impressions can be taken with prepared ink. The albertype, phototype,
and heliotype are collotypes.
Source: Webster’s Unabridged Dictionary 1913 Edition