Plasticine, a brand of modelling clay, is a putty-like modelling material made from calcium salts, petroleum jelly and aliphatic acids. The name is a registered trademark of Flair Leisure Products plc. Plasticine is used extensively for children's play, but also as a modelling medium for more formal or permanent structures. Because of its non-drying property, it is a popular choice of material for stop-motion animation (including several Oscar-winning films by Nick Park). The brand-name clay is mentioned in music, such as the "plasticine porters" in Lucy in the Sky with Diamonds and the song Plasticine by Placebo.