An ambrotype is an early type of photograph in which a glass negative appears positive when placed on a black background.

Thomas Feldvebel has written:

'The ambrotype, old & new' -- subject(s): Ambrotype

An ambrotype image on red tinted glass. The tint eliminates the need for the black background. I've read that the image must be removed from the frame in order to detect whether or not it is a ruby ambrotype.

A tintype is a photograph made by creating a direct positive on a thin sheet of metal coated with a dark lacquer or enamel. An ambrotype is a photograph made by creating a positive image on a glass plate coated with a collodion emulsion. The main difference is the base material used - metal for tintypes and glass for ambrotypes.

If the case is a typical Ambrotype case, and the image is a true Ambrotype, no, a magnet will not stick, since there is no metal in either. The Ambrotype is on glass, the case is made of wood and leather or cloth, or of thermoplastic and the metal frame that surrounds the image is made of non-magnetic brass. A tintype, on the other hand, is made from sheet iron, and a magnet will stick, though it would take a fairly powerful magnet to stick through a layer of wood or plastic between. A magnet will stick directly to the back of a tintype plate, however. To cover all the bases, neither will a magnet stick to a Daguerreotype, since the Daguerreotype plate is silver on copper, neither of which is magnetic.