The first step in reknotting a hole in handknotted pile is to recreate the warp on which the pile rests.
The warp is woven into uncompromised pile at a short distance from the hole. The horizontal strands, pictured above, made of cotton, are the recreated warp.
After the warp is recreated, the weft must be recreated (the vertical strands pictured above). Together the warp and weft form a grid-like structure which will ensure that the pile, once reknotted, will last as long as the rug itself. Note that this kind of handknotted rug repair is a very different approach from the quick-fix patching repair approach. The patching approach involves simply patching in sections of other rugs into a hole. Patching is a temporary fix at best because patches are only sewn into a rug, not rewoven into the pile. .
After the warp and weft are recreated, it is time to start reknotting the pile. The longer blue, red, and white yarn strands in the bottom right hand corner are the beginning of the knotting process. --www.traditionalrugrepair.com