The process of reweaving a hole is a complex, two-step process.
Step 1) The first and most vital step is to rebuild the foundation of the carpet. After cleaning the rug thoroughly, the broken foundation fiber has to be repaired and extended to make it able to reweave. If the foundation is not constructed properly, the repair will not be as effective and will not last long. A good rug repair depends on laying a solid foundation.
Step 2) During the second step, wool threads are then sewn to cover the hole, using the exact density and pattern as the foundation. The master weaver painstakingly matches warps, wefts, and knots so that they are as close a match as possible to the original. After the hole is fully repaired, the area is trimmed down so that it matches the rest of the pile height.
Applying a patch to repair a hole in a rug or doing a full restoration is only possible if the area around the hole is in fairly good condition. If the pile is not thick enough, it can be difficult to hide the stitching.