Reproduction and impression
From the beginning of the 19th century, progress in the realms both of photography and of printing finally enabled direct reproduction of a photographic image in a print. A large number of illustrated magazines were born.
From the 1880s, the phototype process made it possible to produce a large quantity of quality prints. The print had to be affixed into the pages of the book designed for this purpose. Heliogravure, a very beautiful process which required that the image be printed onto special paper, was used for art books.
From 1890, process engraving (duotone) finally meant that the image and text could appear on a single document, opening the way to large-scale production of illustrated magazines and other publications. The original image had to be in the form of an engraved image, made up of variable-sized engraving points according to the density of the tone which was to be reproduced. This was copied onto a metallic plate where each point was pushed into relief in order to receive the printing ink. In this way, photography integrated text, and the page could be printed in one go.
Reproduction cameras designed for photographic copying of documents up to the largest sizes were developed, with adapted lighting; the document being reproduced needed a high quality perfectly uniform light. To begin with, natural light was advocated for this operation, giving way in due course to widespread use of arc lighting.