Chrysotype (also known as a chripotype or gold print) is a
photographic process invented by
John Herschel
Sir John Frederick William Herschel, 1st Baronet (; 7 March 1792 – 11 May 1871) was an English polymath active as a mathematician, astronomer, chemist, inventor, experimental photographer who invented the blueprint and did botanical wor ...
in 1842. Named from the
Greek for "gold", it uses
colloidal gold
Colloidal gold is a sol or colloidal suspension of nanoparticles of gold in a fluid, usually water. The colloid is usually either wine-red coloured (for spherical particles less than 100 nm) or blue/purple (for larger spherical particl ...
to record images on paper.
Processes
Herschel's process
Herschel's system involved coating paper with
ferric citrate
Ferric citrate or iron(III) citrate describes any of several complexes formed upon binding any of the several conjugate bases derived from citric acid with ferric ions. Most of these complexes are orange or red-brown. They contain two or more Fe ...
, exposing it to the sun in contact with an
etching used as mask, then developing the print with a
chloroaurate
Chloroauric acid is an inorganic compound with the chemical formula . It forms hydrates . Both the trihydrate and tetrahydrate are known. Both are orange-yellow solids consisting of the planar anion. Often chloroauric acid is handled as a solutio ...
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
Ferric ammonium oxalate (ammonium ferrioxalate, ammonium tris(oxalato)ferrate) is the ammonium salt of the anionic trisoxalato coordination complex of iron(III). It is a precursor to iron oxides, diverse coordination polymers, and Prussian Blue. T ...
to print out
palladium
Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself na ...
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.
Puckett's process
Richard Puckett, an American photographer, announced in the March/April 2012 issue of View Camera magazine a chrysotype process that uses
ascorbate
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) and ...
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.
Originally the process was named the Texas Chrystoype; following a major revision of the formula in 2017, Puckett renamed the process the Chrysotype Supreme.
Literature
The modern chemist and photographic historian
Mike Ware published the first books covering the subject of chrysotype in 2006, ''The Chrysotype Manual: the science and practice of photographic printing in gold'' and ''Gold in Photography: the history and art of chrysotype''.
References
{{Reflist
External links
The Chrysotype Supreme Formula by Richard PuckettTexas Chrysotype Formula by Richard PuckettPhotographic Printing in Colloidal Gold
Ware, M. The Journal of Photographic Science 42 (5) 157-161 (1994).
Photographic processes dating from the 19th century