White knots – Most rugs have cotton foundations. Cotton warps run throughout the entire length of a rug, and cotton weft threads run left to right and are the means by which each row of wool knots are packed into straight line. During the weaving and packing process, cotton warps and wefts will break. A broken warp or weft cannot be replaced, so the two broken pieces are tied in a knot and the weaving proceeds. This results in white “knots” in the field of the rug. Most times these cotton knots are cut down shorter than the wool face fibers, and they are “hidden.” Over time wearing of the wool reveals these knots and they look like freckles throughout the rug. These can many times be blended away with textile dye.
