The fur is the short, soft hair of mammals that grows next to the skin and under an outer covering of long, coarse hair. Before hides are cleaned and dressed, they are called pelts. To be made usable, they must be thoroughly cleaned and stretched, and the skin must be tanned to a sort of leather. The coarse outer hairs are also made to drop out, and the true fur hairs remain. Some furs are afterward dyed to make them more beautiful. Sometimes cheap furs are dyed in imitation of more expensive ones. All skins are irregular in shape and differ much in color in different parts. They are therefore cut into pieces and then fitted together again according to colors or tints. This requires skillful sewing of the pieces so that the seams will not show. A coat of a valuable fur is often made from a great number of small pieces.
   Some of the principal fur-bearing animals are the sable, marten, mink, beaver, otter, seal, chinchilla, fox, muskrat, and raccoon. Many fur-bearing animals are trapped wild. Also, fur farms have been developed where fur-bearing animals are raised for their pelts.