A Tintype is a one of a kind photograph that uses the wet plate collodion process on a blackened piece of metal.
Originally developed in 1848 by sculptor Frederick Scott Archer, the wet plate collodion process revolutionized the world of photography by offering the general public an affordable and relatively accessible opportunity to have a photograph taken of themselves or a loved one. Archer’s original process, called an ambrotype, involved pouring salted collodion onto a glass plate which was then sensitized with a silver nitrate solution. The light sensitive plate was then loaded into a camera, exposed to light through a lens, and then chemically processed to reveal a negative image of the subject. The resulting glass plate negative could then be printed on similarly sensitized paper to create any number of copies of the photograph or was sometimes displayed with a black background which had a visual effect of reversing the image to a positive. Previously, if one wanted to have a portrait done, their only option was a daguerreotype which was prohibitively expensive to the average person and couldn’t be replicated due the image being made on a copper plate. In 1853, Adolphe-Alexandre Martin modified Archer’s collodion process by using a thin piece of blackened iron instead of a plate of glass. This version which was cheaper, lighter weight and very durable was named a Tintype or Ferrotype and became the most common form of photography during the 1860s and 70s.