Cyanotype Prints

Cyanotypes, are one of the earliest photographic techniques, originally discovered in 1842. They are recognized by their rich Prussian blue monochromatic prints. Cyanotypes we commonly used during the 20th century as an inexpensive method for reproducing photographs, documents, maps and plans, and they are the source of the architectural term “blueprint.” They are also well known for their use in making impressions of biological specimens on site and in the field (“photograms”). Cyanotypes were used famously used by Anna Atkins (1799-1871), a prominent botanist and photographer. In October 1843, Atkins became the first person to produce and photographically illustrate a book using cyanotypes.

These cyanotypes are rendered under direct exposure to sunlight. Before exposing under direct light, a transparency or photographic “negative,” is layered over pretreated paper. Watercolor paper is treated with two chemicals, mixed beforehand. Part A: Potassium Ferricyanide—A red iron salt used with Ferric Ammonium Citrate for cyanotype. Part B: Ferric Ammonium Citrate—A light-sensitive iron salt used with Potassium Ferricyanide for cyanotype.