Woodburytype

The Woodburytypie, also referred to as Photoglyptie, is a printing method that was developed in 1864 by Walter B. Woodbury and 1866 first used in a publication. The term covers both the photochemical process, and the pressure thus produced. In the years 1870-1900 it was a popular method for high-quality book illustration. It was the only commercially successful method to reproduce the finest gradations of photographs in print. The printing process produces the Woodburytypie - similar to the light pressure continuous gray curves without grid by forming a dye reliefs.

For this, a chrome gelatin film is exposed under a photographic negative. The chrome hardened gelatin from proportional to the amount of light. The chrome gelatin print is developed in hot water so that the unhardened gelatin constituents are flushed out. After drying the resulting gelatin relief is pressed with a pressure of 5000 psi in a lead plate and molded by it. In this Mater ( gravure form ) pigmented gelatin is filled - as it is also used in the pigment printing process - and transferred after scraping off the surface of the pigment ink from the recesses on paper. Thereby forming on the paper, a dye relief which generates different gray-scale values ​​depending on the taken from the wells of the plate the amount of dye.

The Woodburytypie was further developed into a three-color printing process, the Photoglyptie. There are three pressure plates are made, which are printed with red, yellow and blue-colored gelatin over each other.