Photographic Print Toning

Print Toning is a photographic process performed on silver-based black-and-white photographic prints to change the color of the photograph. Some photographic toning processes while printing have the capability to improve the chemical stability of the print and also allow its longer longevity, while few other toning processes make the print less stable.

Most of the Photographic Print Toners are used by replacing the metallic silver effect of the print in the emulsion with a silver compound. These compounds are made of silver sulfide (Ag2S) in case of sepia toning. This compound is known to be more stable than metallic silver and can be found in different colors (and tinges). Many old image prints are renewed back through its toning process with sepia toner.

However, different toning processes deliver different colors to the final print of the photograph. Exceptions are in cases when the printer chooses to tone down some of the parts of the print more than its surroundings.

Types of Photographic Print Toning:

Selenium toning in photograph is popular in the archival toning processes, while converting metallic silver to silver selenide. It includes a diluted toning solution where selenium toning transforms into a red-brown tone and a strong solution gives a purple-brown tone. The change in the color texture is highly dependent on the chemical make-up of the photographic emulsion. Such photographic toning has a drastic effect on a Chlorobromide paper print while a little effect on pure bromide paper prints. However Fiber-based photographic prints are more responsive to selenium toning.

Sepia toning picture was first taken in Chicago, Illinois, in 1949. 'Sepia' is coined from the name of an artists' pigment made from the Sepia cuttlefish, found in the English Channel, Sepia officinalis, the Common Cuttlefish. In sepia toning in Photographic Prints consists of chemicals that convert the metallic silver in the print to a sulphide compound (resistant to the environmental pollutants e.g. as atmospheric sulphur compounds).

Sepia Photgraphic Toning can be found in three forms:

1. Sodium sulphide toners
2. Thiourea (or 'thiocarbamide') toners
3. Polysulphide or 'direct' toners

Other significant Photographic Print Toning includes Metal replacement toning, Dye toning and Digital toning.