Felt is a textile that is produced by matting, condensing, and pressing fibers together. Felt can be made of natural fibers such as wool or animal fur, or from synthetic fibers such as petroleum-based acrylic or acrylonitrile or wood pulp–based rayon. Blended fibers are also common. Natural fiber felt has special properties that allow it to be used for a wide variety of purposes. It is "fire-retardant and self-extinguishing; it dampens vibration and absorbs sound; and it can hold large amounts of fluid without feeling wet..."

Fulling, also known as tucking or walking, is a step in woollen clothmaking which involves the cleansing of woven cloth to eliminate (lanolin) oils, dirt, and other impurities, and to make it shrink by friction and pressure. The work delivers a smooth, tightly finished fabric that is insulating and water-repellent. Well-known examples are duffel cloth, first produced in Flanders in the 14th century, and loden, produced in Austria from the 16th century on.