Heddle

A heddle or heald is an integral part of a loom. Each thread in the warp passes through a heddle,^[1] which is used to separate the warp threads for the passage of the weft.^[1][2] The typical heddle is made of cord or wire and is suspended on a shaft of a loom. Each heddle has an eye in the center where the warp is threaded through.^[3] As there is one heddle for each thread of the warp, there can be near a thousand heddles used for fine or wide warps. A handwoven tea-towel will generally have between 300 and 400 warp threads^[4] and thus use that many heddles.

In weaving, the warp threads are moved up or down by the shaft. This is achieved because each thread of the warp goes through a heddle on a shaft. When the shaft is raised the heddles are too, and thus the warp threads threaded through the heddles are raised. Heddles can be either equally or unequally distributed on the shafts, depending on the pattern to be woven.^[1] In a plain weave or twill, for example, the heddles are equally distributed.

The warp is threaded through heddles on different shafts in order to obtain different weave structures. For a plain weave on a loom with two shafts, for example, the first thread would go through the first heddle on the first shaft, and then the next thread through the first heddle on the second shaft. The third warp thread would be threaded through the second heddle on the first shaft, and so on. In this manner the heddles allow for the grouping of the warp threads into two groups, one group that is threaded through heddles on the first shaft, and the other on the second shaft.

While the majority of heddles are as described, this style of heddle has derived from older styles, several of which are still in use. Rigid heddle looms, for example, instead of having one heddle for each thread, have a shaft with the 'heddles' fixed, and all threads go through every shaft.