Core-Spun Yarns: - Consist of a filament base yarn, with an exterior wrapping of loose fiber which has not been twisted into a yarn. Polyester filament is often wrapped with a cotton outer layer in order to provide the strength and resiliency of polyester, along with the moisture-absorbent aesthetics and dye affinity of cotton. Sewing thread as well as household and apparel fabrics are made from these yarns.