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Guide to Early Photographic Formats and Processes in the Special Collections and Archives Research Center

Historical Context

Traditionally, to create an etching, a metal (e.g. copper, zinc or steel) plate is covered with a waxy, acid-resistant ground, a coating made of asphaltum, rosin, beeswax, and tallow. An etching needle is then used to scratch through the ground, exposing the metal plate in a design of the artist's choosing. The plate is then dipped in an acid bath; the ground protects the parts of the plate untouched by the etching needle, and the metal is eaten away by the acid in only those places exposed by the artist's design. Once the design has been etched, the remaining ground is removed and the plate is inked. Excess ink is then wiped from the plate, and the plate is placed in printing press with a sheet of paper.

Light sensitive polymer plates later allowed for photorealistic etchings (sometimes referred to photo-etchings). To create a photo-etching, a photo-sensitive coating is applied to the plate, and light is projected onto the plate as a negative image to expose it. Photopolymer plates are finished in either a hot water or chemical bath.

Collections

Buildings Photographic Collection, 1880-2002
The Building Photographs collection documents Oregon State University buildings, grounds, and facilities as well as a limited number of other notable buildings in Corvallis. The collection also includes approximately 20 line drawings of buildings located on other Oregon University System campuses. Images from this collection have been digitized and are available in Oregon Digital. Etchings can be found in Box 01 (Images #143, 148, 215-216, 228, 259).