Taxidermy specimens are usually the centrepiece of dioramas. Since they must entertain, as well as educate, specimens are set in lifelike poses, so as to convey a narrative of an animal's life. Smaller animals are usually made with rubber moulds and painted. Larger animals are prepared by first making a clay sculpture of the animal. This sculpture is made over the actual, posed skeleton of the animal, with reference to moulds and measurements taken on the field. A papier-mâché mannequin is prepared from the clay sculpture, and the animal's tanned skin is sewn onto the mannequin. Glass eyes substitute the real ones.