A fabric-based item may include fabric formed from intertwined strands of material. The fabric may include first and second fabric layers that at least partially surround a pocket. Initially, the pocket may be completely enclosed by the first and second layers of fabric. A shim may be placed in the pocket before the pocket is closed. An opening may be formed in the first layer of fabric to expose a conductive strand in the pocket. The shim may prevent the cutting tool from cutting all the way through to the second layer of fabric. After cutting the hole in the first layer of fabric, the shim may be removed and an electrical component may be soldered to the conductive strand in the pocket. A polymer material may be injected into the pocket to encapsulate the electrical component. The polymer material may interlock with the surrounding pocket walls.