Calotype

A process introduced in 1841 by William Henry Fox Talbot, using paper coated with silver iodide. The term calotype comes from the Greek καλός (kalos), "beautiful", and τύπος (tupos), "impression". 

Cyanotype

A process that produces a cyan-blue print. Engineers used the process well into the 20th century as a simple and low-cost process to produce copies of drawings, referred to as blueprints. The process uses two chemicals: ammonium iron citrate and potassium ferricyanide.

Van Dyke Brown

An early photographic printing process. The process was named due to the similarity of the print color to that of a brown oil paint named for Flemish painter Van Dyck.