Generally sheepskin rugs are made from skins with finer and softer wools than those used in woven rugs. Sheepskin rugs are the skins of sheep with the wool fibres remaining in their natural state and are then permanently fixed during the tanning process to the skin. Wool rugs are made from stronger carpet wool fibres woven or injected into a backing material. They use wool types that are strong and suitable for walking on and intricate patterns can be achieved in the weaving process. Patterns in sheepskin rugs are achieved by piecing together portions of different sheepskin rugs that have been dyed different colors.