This article covers the results of literature research performed to examine the various 19th century techniques used to transfer the thin collodion layer from a glass plate negative to another support. Techniques for the transfer of collodion were often described and probably extensively used, but only a few examples are known today. In the second part of the publication, the conservation treatment of a collodion negative made in Mexico in 1881 by French photographer Désiré Charnay (1828–1915), will be described. This negative belongs to the Musée du Quai Branly, Paris.