Purists agree an Oriental rug refers to one that was hand knotted or woven, not machine made, from any number of countries. These include China, India, Tibet, Persia, Turkey, Nepal, Afghanistan, and Pakistan in Asia, and Morocco and Algeria in North Africa.
To construct such a rug, we need a loom, which is a large wooden frame with evenly spaced pegs on long, parallel beams. More people use a vertical loom over a horizontal, flat one. Next, in mapping out a traditional design, you would decide on the border of the rug, the centerpiece, and other patterns in the "field," or background. Once you spun and dyed all the colors of wool, silk, or even yak hair, you could begin weaving.
The structural components of the rug are the warp, weft, and woof. Stringing cotton tautly across the top and bottom pegs of the loom forms the warp. For a stand-up loom, the warp runs up and down. The weft is the other set of strings, running perpendicular to the warp, which are threaded in and out of the warp. In a Kilim, or flat rug, the weft creates the design with this weaving. But in a knotted rug, the woof creates a more complicated pattern out of individual knots of wool tied onto the warp. Over centuries, this basic technology has not changed.
The knotting process is the most intricate and time intensive. An area rug might take months to knot, with five workers making 6,000 knots a day! Following the original design, and working from the bottom up, you would build rows of knots in various colors. In between those rows, the weft holds the knots in place and strengthens the rug. Eventually, you would have an uneven rectangular surface of millions of knots.
You would level the surface by trimming the knots to the same height and creating a springy, soft pile. Then the rug can be liberated from its loom by trimming the warp from the pegs. These strings are often tied off and left as the familiar fringed edge. Finally, you would wash the rug and stretch it to give a lush appearance.
Although machines can make rugs that resemble true Oriental rugs, they merely loop and weave thread to imitate real knotting. Also, machine-made rugs frequently use materials inferior to silk, cotton, or wool, such as rayon and other synthetic fibers, which dealers often try to pass off as authentic.