"Dolls" Print from the Doll Exhibit, Museum of Science and Industry Poster Brand new and in perfect condition. Print is 22" x 28" Collotype printing A planographic process: Collotype is a photomechanical printing technique that, like lithography, uses the principle that water repels oily ink. Gelatin-coated plates: Instead of a stone, collotype uses a glass plate coated with a layer of gelatin that has been specially treated to "reticulate" or form a fine, crinkled pattern when washed. Ink absorption: The areas of the gelatin that receive less light become softer and absorb more ink, while the more-exposed, harder areas absorb less ink, creating a continuous tone image. Continuous tone: The result is a continuous tone image with a unique look that is different from screened methods and is valued for its photographic quality.