WARM FABRIC can be described as two materials, FLANNEL and WOOL. FLANNEL is a soft, lightweight fabric that is usually made from cotton or synthetic fibers. It is often used to make clothing such as shirts and pajamas. WOOL is a natural fiber that is obtained from sheep and other animals. It is often used to make sweaters, coats, and blankets due to its insulating properties. Both FLANNEL and WOOL are popular choices for warm fabrics.