A warm fabric with a soft, close nap, flannel may be in a plain or twill weave. It is brushed to create the nap, and this may be on one or both sides. If woolen, it can be in a plain or twill weave, while worsted flannels are right-hand twills, finer and appreciably more substantial.
Flannel was originally always wool (the name is derived from the Welsh word for flannel, gwlânen, which is derived from gwlân, “wool”). It is now found in wool blends, often with cotton.
Uses: Jackets, suits (men’s particularly of worsted flannel), dresses, shirts, skirts