Carbon Printin

On April 15, 1864 a new photographic process was patented, carbon printing. “Why should we have a multiplicity of processes when we have one which can give us any result we wish and is permanent, too? We can now have our picture printed in black like platinotype, in red, sea green, blue purple and several shapes of sepia nd brown…but what of that? Are we going to let a process with all these advantages be unused because it is difficult to work?” This was written by J B Johnston, the man who patented this new technology. He mentioned the difficulties that Carbon Printing presented as a deterrent, the process simply put is printing a negative onto a tissue containing carbon and other pigments in a gelatin base, previously made light sensitive in a bath of potassium bichromate then transferring the image to a paper base and stripping off the backing of the tissue. Here is a link the a five step description of the Carbon Printing process http://www.edinphoto.org.uk/1_early/1_early_photography_-_processes_-_carbon_print.htm
There are definite gripes with how involved the carbon printing process is. It relies on gelatin, sunlight (uv), pigments and timing. Now, the pigments are one of the reasons this process was a better option than it’s predecessors. Because the carbon printing process uses pigments instead of dye it can achieve a wide array of color. Pigments had and have been used by some of the great painters of our times so I guess it was simply a matter of time before photography as an art form followed suit. Obviously color been considered in regards to photography before the carbon printing process was achieved, the issue was stability and the use of pigment was that x factor that allowed the appropriate stability. A more recent example of the stability that pigment offers is in automobile paint. But, there are examples of pigments being used for their ability to retain their color dating all the way back to the tombs of the Valley of the Kings and the frescoes of Pompeii. It is an admittedly time consuming process but, it’s effectiveness and beauty have allowed for it’s use even today.
There are two major variations of the carbon transfer process, single and double. Single transfer the sensitized tissue is developed directly on its support, double the sensitized and exposed tissue is developed on a temporary support before it’s final support.
It is considered the “aristocrat” of the photo developing world, time consuming, exact, artistic, and beautiful. It has been around since the mid 1800’s, patented in 1864 and still used today.



http://en.wikipedia.org/wiki/Carbon_print