Caffenol
Caffenol is a photographic alternative process whereby phenols, sodium carbonate and optionally Vitamin C are used in aqueous solution as a film and print photographic developer.[1][2]
Other basic (as opposed to acidic) chemicals can be used in place of sodium carbonate, however sodium carbonate is the most common.[1]
There are many formulas for caffenol. All are based on preparations which contain caffeic acid (i.e. coffee or tea) and a pH modifier, most often sodium carbonate.[2][3] The chemistry of caffenol developers is based on the action of the reducing agent caffeic acid (which is chemically unrelated to caffeine).[1]
History
The Technical Photographic Chemistry Class at RIT in 1995 led by Dr. Scott Williams developed a method of developing photographic film using standard household items. The tested mixtures of tea and coffee combined with agents to balance the pH and successfully made printable images for exposed film.[1] At the time they did not call it "Caffenol", but the methods they developed later became commonly called Caffenol.
