A tintype, also known as a melainotype or ferrotype, is a photograph made by creating a direct positive on a thin sheet of metal coated with a dark lacquer or enamel and used as the support for the photographic emulsion.

What is a Ferrotype plate?

: a highly polished black-enameled or chromium-plated metal sheet that is used in ferrotyping.

How do you identify a tintype?

A tintype is an image created on a thin sheet of metal. If you don't know whether you have a tintype, here's a trick: A magnet will be attracted to a tintype. As you can see on the edges of this photo, the emulsion (image layer) has a tendency to flake off.