The black and white print is a wondrous thing with numerous possibilities beyond sticking it behind glass - it is a tool in greater artistic expression.
The first thing to realize about the black and white print is how it differs from a color print. In both cases, a print is made of a gelatin matrix which holds the silver. In a color print, the silver is attached to dyes which produce the color - while the black and white print the silver is left (producing black through shades of gray). This concept becomes more important with two of the processes that can be preformed on a black and white print. If one was to bleach a color print, the resulting geletin densities would have little to do with the colors that existed previously.
- Hand Tinting
- Photographic Toning
Toning a photograph is often done to increase the archival nature of the print - often allowing it to exist for a very significant length of time. This is often seen with the sepia toning in old west photographs. The toning process bleaches out the silver from the gelatin matrix and then replaces it with some other compound (selenium, copper, gold, sepia , or many others). Toning a photograph will change the hue - going from black to white to a copper to white or blue to white - this often changes the levels of the grays (most of the time making the mid-tones lighter). It is possible to tone specific spots of the photograph with the use of masks to prevent the bleach and toner from reaching other portions of the print.
- Bromoil Transfer Process
Just as in the photographic toning, in the bromoil transfer process a black and white print is bleached to remove the silver from the print. At this point, print is tanned and dried so that it will accept water in the less dense (white and highlight) portions of the gelatin matrix. After soaking the print again in water an oil based ink is applied to the surface. The white areas (with water) reject the oil while the dark areas accept it. After inking the matrix it is applied to an art paper and the image has been transfered. The use of a brush on the print allows the artist to change the emphasis or subtly alter the image. The artist is by no means required to stick with using a black oil and can take this opportunity the add color to the photograph.