Cyanotype is a historic photographic process from the early 1840s and was introduced to the world by Sir John Herschel in 1842. It is an iron based process that combines two chemicals to make a light sensitive liquid, which is then coated onto watercolour paper. When washed in water after exposure in the sun or under a UV light, the image turns a deep blue. Cyanotype is the basis for early blueprints, and was used to record the structure of plants, algae, lace and other finely detailed items. Later in the century when cyanotype paper was commercially produced for sale to the general public, it was also used to print proofs of peoples snapshots for albums. Today, cyanotypes are a great introduction to historic process printing methods, and more people are discovering the beautiful blue tones for themselves.