Cyanotype A process discovered by John Herschel in 1842, cyanotype is one of the most environmentally benign printing processes. Using only iron-based chemicals and washed in cold water without fixatives, the name derives from the unique blue colour of the prints.
VanDyke Brown Also developed by John Herschel, VanDyke Brown is named after the tones which resemble renaissance art. Using a mix of iron-based and silver-based chemicals, it gives prints of a characteristically red-brown colour.