GMB Cyanotype

The Guggenheim Museum Bilbao in cyanotype made by Charlotte Boiron.

The cyanotype is a process, which produces discovered in the 19th century that produces a Prussian or cyan blue photographic print. In this process, a photographic negative is placed on photosensitive paper—coated with a solution of potassium ferricyanide and iron citrate— and when exposed to sunlight, an image is developed that can be then fixed with water.