An essential part of a loom. Each warp yarn has to be threaded through the heddle which is suspended from a shaft. The heddle can be made of thick cotton or nylon threads, fine cords, metal or twine. It is the heddle that lifts and lowers the prescribed warp yarns, forming the shed, for the weft shuttle to pass through to create the weave. Heddles have to be the width of the fabric to be woven as every warp yarn has to go through it, so there can be hundreds or even thousands of heddles.