The finest yarn comes from sheep that have been bred for centuries to produce lanolin rich wool. The wool is then carded and spun by hand, and eventually colored by master dyers. The wool is left in its natural form, retaining essential oils, which protect wool and keep it strong over time.
Most rugs on the market today are woven with highly processed New Zealand wool. The wool is bleached and stripped of its oils, and then machine spun into overly consistent yarn. Although these rugs are soft and can be woven with tighter knots, the yarn is dead and breaks down over time.