Tintype, also melainotype and ferrotype, is a photograph made by creating a direct positive on a sheet of iron metal that is blackened by painting, lacquering or enamelling and is used as a support for a collodion photographic emulsion.

The process was first described by Adolphe-Alexandre Martin in France in 1853, patented in 1856 both in the United States by Hamilton Smith and William Kloen in the United Kingdom. It was first called melainotype, then ferrotype by a rival manufacturer of the iron plates used; finally tintype

Tintypes are simple and fast to prepare, compared to other early photographic techniques.[2] A photographer could prepare, expose, develop, and varnish a tintype plate in a few minutes, quickly having it ready for a customer. Earlier tintypes were sometimes placed in cases, as were daguerreotypes and ambrotypes; but uncased images in paper sleeves and for albums were popular from the beginning.

Photographers usually worked outside at fairs, carnivals etc. and as the support of the tintype (there is no actual tin used) is resilient and does not need drying, photographs can be produced only a few minutes after the picture is taken.

(Source: Wikipedia)

See also: Making the Positives: Tintype