Note: Rayon-based carbon fibres have a more isotropic structure than similarly heat-treated polyacrylonitrile (PAN)- or mesophase pitch (MPP)-based carbon fibres. Their Young's modulus values are therefore drastically lower ($100\text{GPa}$; tensile strength $100\text{MPa}$). Rayon-based carbon fibres can be transformed into anisotropic carbon fibres with high strength and Young's modulus values by hot-stretching treatment at temperatures of approximately $2800\text{K}$.