Carbon fiber is basically very thin strands of carbon. The strands can be twisted together, like yarn. The yarns can be woven together, like cloth. To make carbon fiber take on a permanent shape, it can be laid over a mold, then coated with a stiff resin or plastic most commonly (epoxy resin) which requires 24 to 50 hours to solidify after it's infused into the carbon fiber. Also because the fibers are entirely carbon, their density is only about 1.6 grams per cubic centimeter (g/cm3), it even beats the lightest structural metal, magnesium, which has a density of 1.8 (g/cm3).