 Change and transience are marked themes in the process art movement.The Guggenheim Museum states that Robert Morris in 1968 had a groundbreaking exhibition and essay defining the movement and the Museum Website states as "Process artists were involved in issues attendant to the body, random occurrences, improvisation, and the liberating qualities of nontraditional materials such as wax, felt, and latex.Using these, they created eccentric forms in erratic or irregular arrangements produced by actions such as cutting, hanging, and dropping, or organic processes such as growth, condensation, freezing, or decomposition".