Unidirectional fabrics are made by using high performance fibers such as carbon, basalt and glass in weaving, usually in the warp direction (0°). In the weft direction (90°) of unidirectional (UD) fabrics, also called one-way or uniaxial, there is usually a thin yarn of glass fibers or polymers. The yarn in the weft direction has no structural function such as flexural or tensile strength. The tensile strength and bending strength of the fabric is in the warp direction (0°) of the high performance yarn. Unidirectional woven fabrics are made in different structures depending on the type of composite or reinforcement.