"The making of a death mask is a messy business – literally. They are difficult to make and the best position for the corpse is not lying down but sat up (as you can see in the picture). The shift from sculpture to masks came about in the Middle Ages when the art of waxwork and plaster casting became more sophisticated. The tradition evolved from royalty to eminent people and continues to this day. Another use, rather than in memoriam for an individuals was for the scientific study of human physiognomy. It was said that experts could tell criminals from the shape of their heads. Casts were also used to record and collect data on the racial differences in the human head."- More
