Léon Vidal conducted successful early experiments in color collotypes in the late 1870s. — “Photochromie”, 1872 and 1874 patents using a woodburytype with chromolithographic under printings, on specially prepared Woodbury paper – the Photochromie used a series of registered lithographic colors manually separated, to produce a color image, not necessarily accurate to reality, printed over each other and then have a Woodburytype, in registration, placed over them yielding a color print. The use of metallic inks or papers, when dealing with metal objects, such as armor, created startling results. One of the drawbacks was that the prints had to be mounted inside stiff mats due to the need for them to expand and contract with atmospheric conditions. This made it nearly impossible for the process to be used in books. However there are examples of small photochromies that were glued directly to a mount. Maybe it was the size of the large prints that caused the problems. Hanson
The frontis. to this book is one of the very few Vidal photochromies used in books. Among the plates are 9 B&W phototypes by Vidal (Ateliers de reproductions artistique) and by Braun of Dornach.
Hanson, David Checklist of photomechanical processes and printing 1825-1910, 2017 p. 138
Hanson, David A, and Sidney Tillim. Photographs in Ink: [exhibition], May 1-29, 1996, University College Art Gallery, Teaneck. Teaneck: NJ, 1996. plate 17 (alt).
Laureline Meizel. ”Le Trésor artistique de la France” : un cas exemplaire de “ livre-spécimen ” au tournant des années 1870-1880. Etudes photographiques, Société française de photographie, 2012. Fig. 3
A. Hamber, A Higher Branch of the Art, p. 90