Hand Knotted Wool Area Rugs: The construction of a rug makes all the difference in terms of look, texture, quality and durability. Hand-knotted rugs tend to be higher in quality because of the intensive labor required. Weavers tie individual knots to the vertical (warp) yarns that run the length of the rug. These knots create the surface, or pile, of the rug. Generally speaking, the more knots per square inch, the more durable and valuable the rug. Hand-knotted rugs have a fringe on the ends and do not have any sort of backing on them. Created by artisans, no two hand-knotted rugs are the same. Their individuality and uniqueness make them extremely appealing. If used with care, a hand knotted rug can become a family heirloom and last for generations.