"Crewel" has supposedly developed from the medieval name for a ball. It is a thread made up of two twisted plies of worsted wool that are not strandable. As with all animal fibers, it has a very subtle sheen and colours are reflected in a variety of shades, especially in a stitch with varying directions. The crewel wool supplied by this manufacturer has a fantastic soft feeling, still being very strong and not subject to tear easily.