Felt is a material created by matting, condensing and pressing fibers together. It can be made from natural fibers like wool and animal fur, or from synthetic fibers. These can be acrylic, acrylonitrile or wood-pulp based rayon. Blended fibers can also be used. Fun fact: felt is used to mute or suppress the strings on a piano. If you look inside one, you should see a green stripe of this textile.