Photochrom (also called the Aäc process) prints are colorized images produced from black-and-white photographic negatives via the direct photographic transfer of a negative onto lithographic printing plates. The process is properly considered a photographic variant of chromolithography, a broader term referring to color lithography in general. The photochrom process was most popular in the 1890s, when true color photography was first being developed but was still commercially impractical.