Carbon Transfer prints are a very dissimilar medium to other alternative processes that rely on silver or iron-based light sensitive chemicals to produce images. They are also the most time consuming, difficult, and complicated of the alternative processes.
To make a carbon print I first formulate a mixture of gelatin, pigments and other chemicals that is affectionately called "glop." This glop is then carefully poured onto water-resistant paper and allowed to dry. It is then coated with a dichromate, placed in contact with a negative, and exposed to UV light. The dichromate reacts with the light to harden the gelatin in proportion to the densities of the negative. The tissue is then wetted, sandwiched in contact with a final support under heavy weight, and finally placed in hot water to melt the unhardened gelatin, leaving an extremely stable and permanent print.