Shoemaker's WELT is a strip of leather that is sewn around the edge of a shoe to provide extra strength and durability. It is also used to attach the sole to the upper part of the shoe. The WELT is usually made from a thicker leather than the rest of the shoe, and it is stitched in place with a special machine. This technique has been used for centuries and is still used today in the production of high-quality shoes.