After the wool has been colored and processed, it is ready to weave. There are two types of looms: vertical and horizontal. Vertical looms are most commonly found in weaving factories and are nothing more than a sturdy frame, usually made of wooden timbers, designed to hold taut the warp strings upon which the weaver ties rows of knots. Beginning on the ground, the weavers work to the top. They are gradually raised on a type of scaffolding as they come closer to completing the rug.
Vertical looms are more difficult to move than the horizontal looms, which are often found in people’s homes. Horizontal looms were originally used by nomads, and are easy to pack up and move, as the nomads’ lifestyle necessitated. The horizontal loom is basically the same as the vertical loom, except that the rug is woven parallel to the ground. When it is necessary to move the loom to cook, eat, or sleep, it is simply rolled up and put aside until work can begin again.
Looms hold the foundation threads, called the warp and the weft in place so that knots can be tied around them to form the pile. The warp fibers run up and down on vertical looms. The finer a rug’s quality, the thinner the warp fibers are and the closer they are together. Weft fibers simply weave in and out of the warp fibers. Weft fibers separate rows of knots in all pile rugs.
Knots are the yarns woven around the warp and the weft. Knots can be counted from the back of the carpet, and this count can often determine the quality and cost of a rug. The finest rugs have from 400 to 700 knots per square inch. On average, most rugs have from 90 to 250 knots per square inch.
As rows of knots are completed, the weaver must pack them down with a large metal comb. The loose ends of these knots form the pile of the rug, or the part on which we walk. Periodically, the weaver will sheer off some of the extra yarn that has been left on the knots. By trimming the pile, the design becomes sharper.
After the entire rug is finished and taken off the loom, it is sheared once again. At this time extra details can be added by hand carving or embossing the rug. This process involves highlighting certain features of the rug by cropping the surrounding yarns. The shearing and embossing of the rug are perhaps the most difficult tasks and thus require highly skilled workers.