Carbon fiber reinforced plastic (CFRP or CRP), is a very strong, light and expensive composite material or fiber-reinforced plastic. Similar to glass-reinforced plastic, one uses commonly the name of its reinforcing fibers (carbon fiber) for the composite material. The plastic is most often epoxy, but other plastics, such as polyester, vinyl ester or nylon, are also sometimes used. Some composites contain both carbon fiber and other fibres such as kevlar, aluminium and fiberglass reinforcement. Less commonly, the terms graphite-reinforced plastic or graphite fiber reinforced plastic (GFRP) are also used.