Phrenologists and ethnographers used both death masks and life masks (taken from living people) for scientific and pseudoscientific purposes. A death mask is a wax or plaster cast made of a person’s face. Death masks may be mementos of the dead, or used for creation of portraits. It is sometimes possible to tell if paintings have been copied from death masks, because shape of the face is altered by the weight of the plaster during the making of the mould. In some cultures a death mask may be a clay or other item placed on the face of the dead person before burial rites. The best known of these are the masks used by ancient Egyptians as part of the mummification process, such as Tutankhamon’s burial mask. In the 17th century in some European countries, it was common for death masks to be used as part of the effigy of the deceased, displayed at state funerals. During the 18th and 19th centuries they were also used to keep a record the faces of unknown bodies. This is now done with photographs.