Close up of 'Grip Clips' and wooden clothes pins. During the production of a movie, commercial, music video etc., a spring-type clothespin is called a "CP 47", "C47", "47", "peg", "ammo", or "bullet". It is most useful on the set since lights used on film sets quickly become far too hot to touch; a wooden C47 is used to attach a color correction gel or diffusion to the barn doors on a light. The wooden clothes-pins do not transmit heat very effectively, and therefore are safe to touch, even when attached to hot lights for a significant period of time. Plastic or metal clothes pins are not used as plastic would melt with the heat of the lights and metal would transfer the heat making the clothes-pin too hot to touch. People like gaffers, grips, electricians and production assistants may keep a collection of C47’s clipped to clothing or utility belt at all times. Hence the nickname "bullet", as so many crew members clip a number of C47s to their utility belts, much like an old west gunslinger would carry extra bullets on his gun belt.