Ambrotypist

The ambrotype was a cheaper rival to the daguerreotype. A glass plate was coated with collodion, exposed in the camera while still wet, then given a black backing so the negative image showed as a positive. Each picture was one of a kind and was usually kept under glass in a small protective case.

In 1854 James Ambrose Cutting of Boston took out patents on the process. During the 1860s the cheaper tintype, made on thin iron, took its place, so the title belongs mostly to the 1850s and early 1860s.