"Historical Process" refers to the historical traditional processes in Photography prior to the standardization of the darkroom silver print. They include Platinum / Palladium printing (which is considered to be the highest standard in photographic printmaking), Carbon Print process (uses sensitized carbon gelatin tissue), Gum Bichromate, Cyanotype, Salt Print, Bromoil, Van Dyke, and Photogravure. At InkjetMall we sell a lots of stuff for these processes including paper, gravure plates, brushes, chemicals, and more.