The collotype was a photomechanical printing procedure (in graphic arts workshops). Conceived in 1856 by Louis Alphonse Poitevin , it was later perfected by Joseph Albert , for which reason it also spread under the name of Albertipo .
On a matrix made up of a glass plate, a layer of photosensitive emulsion made up of bichromated gelatin was spread, which was subjected to firing, and then impressed by contact with the original photographic negative. The gelatin became more insoluble in the transparent areas thereof. In this way the ink was more easily absorbed in those transparent areas.
This procedure allowed a limited number of 500 copies to be thrown ; because the gelatin deteriorated during the printing process, and sharpness was lost.
Among the photographers who used this system for print runs, Alfred Stieglitz can be mentioned.
Size: 8" x 10"
