When a strand of hair is hand tied to the lace on lace wigs it forms a knot at the root. Many lace wigs are doubled knotted to ensure a secure hold, however, this process results in a slightly more visible knot "nodule" on the lace. These knots are small and can still allow for a natural looking part on your unit. However, many ladies will opt for the knots to be bleached, in this process the knots are chemically lightened to provide a more "invisible" seamless part in the unit. Bleaching the knots are quite common in most human hair units, in many cases only the perimeter is bleached. The drawback to having "bleached knots", is that this weakens the hair at the root, and can result in increased shedding in your unit.
