Stop frame animation, also known as claymation, involves shooting animated characters made of materials like plasticine one frame at a time to create the illusion of movement. Wallace and Gromit used some frame duplication to simulate motion blur. Stop frame animation was also used in the 1970s and 1980s with paper or other rare materials. The frame rate, or number of unique frames per second, determines how smooth the animation appears, with 24+ frames per second appearing most natural.