The whole point of using a loom in weaving rugs or tapestries is to keep the warp under tension so the weft can be drawn through efficiently.  The first method used was to draw the warp tight between two beams held to the ground by stakes at all four corners.  This is the horizontal ground loom and was used to great affect in rug weaving by most of the ancient cultures as far back perhaps as eight to ten thousand years BC.  Maybe the weavers got tired of sitting on the ground.  It must have hurt their backs. 

Around 2500 BC somebody thought of a better way to weave.  With the warp-weighted loom one of the parallel beams would be attached a few feet above the ground allowing the warp to dangle loosely inches from the floor.  Without something more this wouldn’t work very well, of course, as there would be no tension on the warp and the thread would curl up.  But then some genius thought of attaching the warp threads to heavy rocks and thereby put the necessary tension on the warp.  So there you have it, warp-weighted means weights on the warp and the long-suffering weaver could stand or sit on a chair.  The picture on our left is a Greek Vase displaying a warp-weighted loom from about 500 BC. It is referred to as Circe’s loom. Circe, by the way, was the goddess who demanded that Ulysses sleep with her or she would turn him and all his men into swine. Apparently he acquiesced and he and his men were allowed to continue only acting like swine. In any case her rugs, carpets and tapestries were reputedly particularly fine examples of the weaver’s art.