since references to "images" often fail to distinguish between commemorative portrait busts, extant examples of which are abundant, or funeral masks made of more perishable materials, none can be identified with certainty as having survived. the veristic tradition of funerary likenesses, however, contributed to the development of realistic roman portraiture. in roman egypt, the fayum mummy portraits reflect traditions of egyptian and roman funerary portraiture and the techniques of hellenistic painting.