Welt is a term used in Shoe industry that refers to a strip of leather sewn between the insole and the outsole of the Shoe to create greater durability. Welt is also described as a st rip of leather or synthetic attached to the outsole and upper, situated in the crevice between upper part of shoe and sole. For decorative purposes, it may also be only attached to the sole.
Likewise, Welt refers to the top portion of the stocking, were the garter is to be attached. This area is made with a heavier gauge of nylon, doubled over and finished closed.