A structure on which woven cloth is manufactured, comprising a frame set horizontally across vertical supports. The warp threads were tied across the frame from front to back so that they could be wound out as weaving proceeded. The warp was usually arranged so that alternate threads could be raised and lowered, thus allowing the weaver to pass a shuttle containing the weft thread from side to side across the warp. The horizontal loom was developed later than the UPRIGHT LOOM and provided the basis for the development of mechanical looms during later medieval and post-medieval times.