The cross section depicts the shape of the various textile fibers. Each textile fiber offers a distinct cross sectional appearance when seen under a microscope. The shapes vary from round to oval and flat, different shapes determines certain characteristics of the textiles. Though the majority of synthetic fibers have a circular cross section, but the shape could be altered or engineered during the manufacturing process. The cross-sectional shape is responsible for certain physical properties of textile fibers such as the luster of textiles.