Photochrom

Photochrom, Photochrome, Fotochrom or the Aäc process is a process of colorizing from a single black-and-whitenegative with subsequent photographic transfer onto lithographic printing plates. The process is a photographic variant of chromolithography (color lithography). Because no color information was preserved in the photographic process, the photographer would make detailed notes on the colors within the scene and use the notes to transfer the image through colored gels onto the printing plates.