Wet-collodion process, also called collodion process, early photographic technique invented by Englishman Frederick Scott Archer in 1851.

During what period was the collodion negative most popular?

The collodion negative was most commonly printed on albumen paper. Talbot's Calotypes (paper negatives) preceded collodion. For over thirty years, from the 1850s to the 1880s, the wet plate collodion process was the most commonly practiced photographic method around the world.

When were collodion portraits most popular?

The collodion positive, or ambrotype, first appeared in about 1853. By the 1860s the process had largely disappeared from high street studios, but it remained popular with itinerant open-air photographers until the 1880s, because portraits could be made in a few minutes while sitters waited.