n. an early photographic process in which the image is made on an iron plate having a sensitized surface film
the GNU version of the Collaborative International Dictionary of English
n. A photographic picture taken on an iron plate by a collodion process; -- familiarly called tintype.
The Century Dictionary and Cyclopedia
n. A kind of positive photograph, so called because the sensitive film is laid on a sheet of enameled iron or tin; a tintype. The plate is exposed in the camera and then developed in the ordinary way.
Word Usage
"_ It is commonly known under the names of “blue print process,” “negative ferrotype process” and"