First permanent type of photographic print, patented in 1855 and perfected in 1866. The negative was printed onto carbon tissue, then double-transferred to paper. Usually reserved for exhibition prints because it was an expensive and elaborate process.
(Autotype, assembly printing) nonsilver, permanent photographic print popular between 1870 and 1910, produced by exposing a sheet of paper coated with gelatin, carbon black and potassium dichromate against a negative, the gelatin hardening in proportion to the amount of light passing through the negative; a print with a dense, glossy black or deep rich brown tonality, often with slight relief contours thickest in the dark areas
A positive print made by exposing a negative in daylight against a paper coated with pigmented gelatin and sensitized with potassium bromide. During exposure the gelatin hardens in proportion to the amount of light it receives through the negative. The excess pigment is washed away leaving the final image. Using a combination of pigment and potassium bromide versus silver based photographic processes which tend to deteriorate over time, this process was the first permanent photographic process.
a pigment print that relies on the use of a bichromated colloid mixed with a pigment (usually carbon black) for the formation of the print image
a very thick layer of gelatin with pigment in it, unsensitized and, just before you're ready to work it, you sensitize it by soaking it in dichromate, then expose it under a negative and squeegee a sized piece of paper together with that
This photomechanical process, discovered by the French inventor Alphonse Louis Poitevin, is a close relative of the Woodburytype process, but does not usually have the same relief surface. Although both Woodburytypes and carbon prints could have been made with any pigment then available they were usually made in the color that closely resembled that of the photographs being reproduced - usually gray and black for carbon prints. Carbon prints may be more difficult to identify than Woodburytypes. Under magnification there is no visible grain or half tone pattern of regularly spaced dots, but the surface may appear speckled with particles of pigment of dust. When viewed at an angle the surface appears glossy, more so in the shadows than in the highlights.
The first permanent photographic printing process used between 1866 to 1890. Made in three different tones: black, purple-brown, sepia. It is made by using 3 layers of stable pigment in registration on top of each other and requires a minimum of 12 hours to create a single print. Carbon prints are highly sought after and rare.
A carbon print is a photographic print produced by soaking a carbon tissue in a dilute sensitizing solution of potassium bichromate. The solution also consists of carbon, gelatin, and a colouring agent. The process was created as a result of print fading in early photographic processes, and was patented in 1864 by Joseph Wilson Swan.
