to prevent melting. A lapse in the cooling apparatus, even for seconds, can ruin a plastic gobo in a tungsten-halogen lighting instrument. Patterns Theatrical and photographic supply companies manufacture many simple and complex stock patterns. They also can produce custom gobos from customer artwork. Generally, a lighting designer chooses a pattern from a manufacturer's catalog. Because of the large number of gobos available, they are generally referred to by number, not name. Lighting technicians can also hand-cut custom gobos out of sheet metal stock, or even aluminum pie pans. Gobos are often used in weddings and corporate events. They can project company logos, the couple's names, or just about any artwork. Some companies can turn a custom gobo out in as little as a week. Designers also use "stock" gobo patterns for these events—for example, for projecting stars or leaves onto the ceiling. Mechanics/optics The gobo is placed in the focal plane of the lantern (generally an ellipsoidal reflector spotlight or a moving head). The gobo is inserted upside-down and back-to-front. The lighting instrument inverts the projected image. Common sizes See also Bat-Signal Gobo (recording) References Photographic lighting Photography equipment Stage lighting Stage terminology