Carbon Fibre is a graphite fabric especially designed for use in laminates which have critical requirements for maximum stiffness, extremely high tensile (3 times that of steel) and comprehensive (5 times that of steel) strengths, with low weight. Its main function is local reinforcement to improve the strength to weight ratio of highly stressed parts. Carbon fiber is weak in shear strength and impact resistance and should be shielded from abrasion with fiberglass or other materials, such as Kevlar®. This material is categorized by weight per sq. yd. and is sold by the running yard.