Canson® secured a patent for a photographic paper

In 1865 Canson® secured a patent on December 8th 1865 since the process was simpler and cost less than the ones used before then. This Canson® paper cut out the need to use the platinum or gold chloride that toning entailed.
Brevet photographique,
© Musée des Papeteries Canson  et Montgolfier