All of the best-quality handmade rugs are made from wool that is sheared from a live sheep, hence the term, “live wool.” Goat hair, also called cashmere, mohair or angora, and camel hair may also be used. Wool shorn from animals living in cold climate regions is often more durable because it is more dense. Lamb’s wool is especially prized for its springy, yet fine texture. In general, textile experts consider wool one of the softest and most durable natural fibers. It contains lanolin, a substance that makes it water repellant. Wool is insulating, fire-resistant and highly sought-after for its soil resistance, flexibility and resilience. It is also beautiful, readily capturing and reflecting light. And because it absorbs dye so well, wool yarns can be produced in an astonishing array of colors, both brilliant and subtle. When knotted onto a solidly constructed foundation, wool wears like iron. Hand-knotted rugs of the best wool have an expected lifetime of 75 to 100 years and even longer. In fact, a high-quality wool rug improves over time. After many years of use, the wool may even resemble silk because the natural oils it contains rise to the surface of the fibers, polishing the yarn and resulting in a natural sheen.