The cyanotype was the first simple and successfully realized practical non-silver iron process. Discovered by Sir John Herschel (1792-1871) in 1842, a mere three years after the “official” announcement of the discovery of photography, the cyanotype provided permanent images in an elegant assortment of blue values.  Herschel is the same gentleman who coined the words  “positive and negative,” “photograph,” and “snapshot.” He is also credited, in 1819, with discovering that a solution of sodium thiosulfate (which he referred to as hyposulfite of soda) had the ability to dissolve silver chloride and what that particular chemical’s role might be in permanently fixing a photographic image. This is an important bit of information that he passed along to Talbot twenty years later.

The Cyanotype was popular for a short time and the first commercial use of the process was initiated in 1876 at the Philadelphia Centennial Exposition, introducing the adoption of the process for schematic blueprint drawings that would be used by architects, engineers and builders. One other odd historical bit concerning the cyanotype involved Lt. Col. Baden-Powell, founder of the Boy Scouts, who used the cyanotype process to make stamps and money during the siege of Mafeking in the Boer War (1899 – 1902) between Great Britain and the Transvaal.