Tintypes are images made directly in the camera on black anodised aluminium sensitised with silver salts suspended in a collodion based coating. They are all “one off” items – sometimes called “Victorian Polaroids”. Originally “Tintypes were on a black japanned metal base, but most modern ones use thin anodised aluminium.

Ambrotypes are similar, but use a glass plate as the base – the thin collodion negative is exposed directly on the glass and the image shows when it has a black background. The black coating can be directly on the negative surface and the image viewed though the glass, in this case the image is not reversed as it is with a tintype or if the ambrotype is coated on the reverse side to the image.