A Photochrom is a colour image created from a black and white film that has been coloured by transferring it onto a number of lithographic stones, which are fine-grained limestone slabs used for etching or drawing – for each colour, a different stone is used and each image is retouched manually with the desired colour. This procedure, invented in the 1880s, was very fashionable in the 1920s and was mainly used in the commercialisation of travel photographs that tourists of the time could procure as a souvenir of their journey.

**The artist: Adoc-photos**

ADOC-photos is a photographic agency based in Paris and specialising in historic documentation. Most of its collection is intended for use by print media, publishing, and audiovisual professionals. The vast collection held by the agency ranges from the first known photographic images to the most recent, and includes all kinds of illustrations, from historic events to scenes from everyday life, sciences, and travel, celebrities, and topographical points of view. The various sources of ADOC-photos offer as many masterpieces of classic photography as they do unknown amateur works.