In heraldry, ermine is one of the furs used in blazon, representing the skin of the stoat, known in medieval Latin as armenius (Armenian (mouse)). In winter the stoat has white fur and a black tail; heraldic ermine represents a number of skins sewn together, forming a pattern of sable (black) spots on argent (white).
Besides black-on-white, at least three variants of ermine are considered tinctures rather than simply a field of a particular colour or metals semy of ermine spots of another colour or metal. A field of ermines (or counter-ermine) is sable with argent spots. A field of erminois is Or with sable spots, while a field of pean is sable with Or spots.