The process of interlacing sets of threads lengthwise and crosswise to make cloth. The group of threads running the length of the fabric is the warp, and the set running across it is the woof, or weft. Woof thread is woven alternately over and under the warp threads. (Le 13:59) Weaving was often done by women but was also apparently an occupation of men. (2Ki 23:7; 1Ch 4:21) The loom that the Hebrews, Egyptians, and others used for weaving was basically a frame.​—Jg 16:13, 14; Isa 19:1, 9, 10.

Ancient looms were either vertical or horizontal. One type of vertical loom consisted of two upright stakes with a crossbeam at the top. The warp threads hung from it and had weights attached to keep them straight. In some looms a lower beam took the place of weights, and in others this beam could be rotated to serve as a roller for the woven cloth. A common horizontal loom consisted of two parallel beams kept in place some distance apart by four pegs driven into the ground at their extremities. Warp threads were stretched between these beams. The wooden shaft of Goliath’s spear was possibly being compared to such a heavy beam when it was likened to “the beam of loom workers.”​—1Sa 17:4, 7.

On the loom the warp threads were usually separated into two sets, so that the woof thread would pass over one set when drawn across the warp in one direction and under that set when moved across it in the opposite way. For this, two “sheds,” or passages, were needed. In a simple horizontal loom a flat “shed stick” was placed across the warp under alternate warp threads, and by turning it on edge, one “shed” was made, through which the woof thread was passed in one direction. Alternate warp threads attached by loops of thread to a “lease rod” lying on top of the warp were next raised by lifting the “lease rod” vertically from the warp, making another “shed” through which the weft was drawn in the opposite direction across the warp. After each movement across the warp, the woof thread was pressed against the growing cloth with a peg. The weaver drew the weft across the warp with a shuttle, basically a rod carrying the thread. Since the skillful weaver moved the shuttle rapidly, Job could say: “My days themselves have become swifter than a weaver’s shuttle.”​—Job 7:6.

After the cloth had been woven to the desired length and rolled up, the loom worker cut it from the warp threads. (Isa 38:9, 12) Materials commonly used by weavers included animal hair (Ex 36:14; Mt 3:4), wool, and linen.​—Compare Pr 31:13.

Fabrics of varying patterns could be made by using threads of different colors in the warp or the woof or in both. Or woof thread of a particular color might be run only partway in the warp. (Ge 37:23; 2Sa 13:18; Pr 7:16) The loom worker might weave in an irregular manner​—running a set of woof threads over one warp thread and then under two across the warp, and then running the next set over two warp threads, under two, then over one for the width of the warp, as in weaving gabardine today. By variations in weaving methods, a pattern is developed in the fabric even when warp and woof threads are the same color. Aaron, for instance, was provided with a white robe of fine linen woven “in checkerwork.”​—Ex 28:39.