English Photochrom Image - Medium Metal Wall Sign 30 x 20cms. A unique range of hand made metal signs by designAsign - one of the UK's leading specialist metal sign providers.The original Photochrom prints are colorized images which are produced from black-and-white photographic negatives via the direct photographic transfer of the negative onto lithographic printing plates. The process is 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.
