Commonly used to create sculptures, plaster is made by mixing water, lime, gypsum, sand, and other strengthening materials, such as animal hair. The resulting paste can be applied to walls, cast, or, once dried, carved. Since antiquity, plaster has been used for frescoes and reliefs, both in Roman and Islamic architecture. Later, plaster allowed for the easy reproduction of Greek and Roman masterpieces. These cast copies served as teaching aides for artists and academics and were commonly acquired by museums in the 19th century as an economical means to expand collections. Plaster’s adaptable qualities are evident in modern and contemporary works: in the 1960s, Louise Bourgeois embraced the material for its suppleness, using it to create her biomorphic sculptures, while George Segal exploited its ghostly quality to craft intimate body casts of friends and relatives, echoing its use in ancient Greek and Egyptian death masks.