Chrysotype

The chrysotype , also known as gold printing , is a photographic process invented by John Herschel in 1842. He named it after the Greek name for gold (chrysos), because colloidal gold is used to make the photographic paper images .

Herschel coated paper with an emulsion containing ammonium iron citrate and exposed a contact etching to the sun. It was developed with a gold chloride solution. However, no halftone images were created.

British photo historian and chemist Dr. In 1994 Mike Ware improved the process (New Chrysotype) and expanded the tone scale .

Web links

• Mike Ware: Prints of Gold: the Chrysotype Process Re-invented. In: The Scottish Photography Bulletin. No. 1, 1991, ISSN  0269-1787 , pp. 6-8.
• Mike Ware: Photographic Printing in Colloidal Gold. In: The Journal of Photographic Science. Vol. 42, No. 5, 1994, ISSN  0022-3638 , pp. 157-161, ( MS Word-Document ; 105 kB).