Chrysotype
Chrysotype is a photographic process invented by John Herschel in 1842, though it was eclipsed in popularity by Henry Fox Talbot's calotype process. Named from the Greek for "gold", χρυσός, it uses gold chloride to record images on paper. Since then, the process has been rediscovered and reinvented by other practitioners on many occasions with varying success. They include Robert Hunt's 1841 'gold process', Thomas Hennah's 1852 'gold prints', and Alfred Jarman's 1897 aurotype process.
Processes
Herschel's process and derivatives
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.A number of people have attempted to replicate Herschel's original method, including William Russell Young III in 1981 and Owen Davies in 1997. 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 1996, a variant of the palladiotype process which uses lithium palladium complex salts and ferric ammonium oxalate to produce photographic images, many photographers began experimenting successfully with substituting gold for some or all of the gold chloride can be used in place of part of the palladium salt to augment colour and tone. Gold chloride may be used to substitute as much as 80 percent of the lithium chloropalladite.Works cited
Category:Photographic processes dating from the 19th century