Old Process / New Artist

The old photographic process that intrigued me the most was the cyanotype process.

The cyanotype process was invented by the astronomer and chemist John Frederick William Herschel (British, 1792-1871). The name cyanotype was derived from the Greek name cyan, meaning "dark-blue impression." Herschel experimented with the cyanotype process in the 1840s and inspired Anna Atkins, daughter of his friend Dr. John Children, to illustrate her botanical studies with cyanotype photograms.

The general principle of the cyanotype process is the photochemical reduction of iron (III) salts to iron (II) salt that reacts with potassium ferricyanide (red prussiate of iron), forming an intensely blue complex. The process has several simple steps:

1. Selected paper or other material is coated with a mixture of iron (III) salt (today mostly of ferric ammonium citrate) and potassium ferricyanide. The coating must be applied under dim light due to light sensitivity.
   
2. The resulting yellow-greenish layer of sensitized material is dried in the dark.
   
3. The dried, sensitized material is exposed under a negative or other partially or fully
   opaque material (when creating photograms) to strong light (sun or an artificial UV light source), usually in a printing frame that assures good contact between the negative and the sensitized material.
   
4. Light exposure is aided by simultaneous exposure of a sensitometric wedge or timed based on exposure and development of a series of test samples.
   
5. The exposed material is transferred to a water bath to complete the formation of Prussian blue in areas exposed to light and to dissolve any unexposed mixture of sensitizing compounds. Full development of the blue image can be aided by the addition of a hydrogen peroxide solution to the bath. Otherwise, the blue image can be assessed only after the material is fully dried and oxidized by exposure to air. 

A new artist that uses this process: 

• Daniel Coburn
• Daniel Coburn says photography is about ideas. "As image makers we have a vulnerable opportunity to engage with a variety of historical processes, to make images that are beautiful, and rich in concept."

Not all cyanotypes are cobalt blue: Internment toned cyanotype from Waiting for Rapture. Photo by: Daniel Coburn

Sources used:

1. Cyanotype history and process
2. Daniel Coburn - New Artist