Carbon Fibre:

Also called a composite, this is a mixture of a matting of carbon threads and epoxy resin – like fibreglass but using carbon threads instead of glass. Carbon fibre is strong and light, and because the manufacturer can decide which direction the fibres go, the frame can be made stiff in one direction and springy in another. Because all these layers need to be bonded together properly though, it is expensive, and it can also be quite delicate.