Chrysotype

Chrysotype (also known as a chripotype or gold print) is a photographic process invented by John Herschel in 1842. Named from the Greek for "gold", it uses colloidal gold to record images on paper.

Processes

Herschel's process

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. This did not provide continuous-tone photographs.

In 2006, 164 years after Herschel's work with gold printing, photographers Liam Lawless and Robert Wolfgang Schramm published a formula based on Herschel's process.

Processes based on ziatype

Following the introduction of Richard Sullivan's ziatype process in 1997, which uses ammonium ferric oxalate to print out palladium images, many photographers began experimenting successfully with substituting gold for some or all of the palladium. Image quality decays rapidly as the printer approaches 100% gold in a ziatype print.