Chrysotype (also known as a chripotype or gold print) is a photographic process invented by John Herschel in 1842.
Herschel's system involved coating paper with ferric citrate, exposing it to the sun in contact with an etching used as mask, then developing the print with a chloroaurate solution.
Image quality decays rapidly as the printer approaches 100% gold in a ziatype print.
Richard Puckett, an American photographer, announced in the March/April 2012 issue of View Camera magazine a chrysotype process that uses ascorbate with ammonium ferric oxalate to print out on dry paper, with no hydration, fine-grained, continuous tone gold images.
Puckett presented the process at the 2013 APIS (Alternative Photography International Symposium) in Santa Fe, New Mexico.