Anisotropic materials are materials whose properties vary when measured in different directions. Fiber-reinforced materials such as composites frequently display anisotropic properties and can demonstrate great strength when force is applied in the same direction as the fibers, and much less strength when force is applied in the opposite direction. Anisotropy can also be observed in other materials like metals, where processing or forming operations such as rolling or deep drawing have been performed. Materials with uniform directional strength are referred to as "isotropic".