Very helpful devices to maintain the warp width as sleyed in the reed and prevent narrowing. Choose wood or metal; each comes in several sizes:
Temples will improve your selvages, your weaving speed and comfort, improve the quality of your weaving, allow you to get a tighter weave, allow you to get a more even beat and make beating easier. As a result, your wefts will be straight and your selvages will also be better.
Download from Glimakra - How to Use a Temple