The word flannel originated from a Welsh word for wool. The fabric itself can be traced back to 16th century Wales, 17th century France, and 18th century Germany. Flannel was originally made from worsted yard or carded wool. Today, flannel is typically made of wool but can be blended with cotton or a synthetic fabric. It is most commonly known for its ability to keep warm and is typically used for blankets, sheets, and pillow coverings because of this property.