A type of carpet constructed without pile, where the warp and weft threads are woven together to create a flat surface. Examples include kilims, dhurries, and soumaks. Flatweaves are typically reversible, lightweight, and easier to clean than pile carpets, making them popular for casual spaces and warmer climates.
A rug made by punching pile yarn through a stretched cloth base with a hand-held tufting tool and fixing the loops with a glued backing, rather than tying knots by hand around warp and weft threads. Its back shows cloth and adhesive instead of individual knots and feels less soft than a knotted rug's. It ranks below hand-knotted and above machine-made rugs, does not last as long as a knotted rug, and is not considered a genuine Persian or Oriental rug. Because it is sometimes sold simply as "handmade", the term hand-knotted is the one that identifies a knotted rug.
The skeleton of a hand-knotted rug: the warp and weft threads on which every pile knot is tied. Cotton is the usual material in city and village rugs because it barely stretches or shrinks with humidity, so the rug keeps its shape, and it is rigid enough to knot through easily; that same rigidity can carry over into the design, which reads as less fluid than on a wool foundation. Wool, and sometimes goat hair, is typical of tribal rugs, whose weavers can use one material for both foundation and pile; it gives more character but a less straight shape. Silk, being finer, permits very high knot counts. The fringes at each end are the foundation's exposed warp ends, so they reveal its material.
A rug base in which the warp and weft threads are silk rather than the usual cotton or wool. Silk is finer and thinner, so many more knots fit into each square inch; silk-based rugs typically run about 500 to 1,000 knots per square inch (roughly 78 to 155 per square centimeter). It is found mainly in fine traditional city rugs, most commonly Qum and Isfahan, and also in select Tabriz workshops and a special group of Yomut Turkoman rugs. The pile above may be wool, silk and wool, or pure silk.
The two thread systems that make up a carpet's foundation: the warp, the vertical threads strung on the loom first, and the weft, the horizontal threads passed through them between rows of knots. The foundation is usually cotton, though wool is common in tribal and older rugs and silk in very fine ones. Single-weft rugs, standard in the greater Hamadan area, show zigzag rows of white warp dots on the back and have a thinner pile, whereas double-weft construction, standard in fine, tightly woven rugs and in Bijar and Heriz, hides the warp and gives a thicker, denser pile. The warp ends form the fringe, and extra weft passes at each end form the flat-woven kilim end that secures the pile.
A rug base in which the warp and weft threads are wool instead of cotton. It is typical of tribal rugs such as Baluchi, Turkoman and Gabbeh (Gabbeh and Quchan sometimes use goat hair instead), turns up in some Qashqai, Shiraz, small Bakhtiari and Iranian Azerbaijan pieces, and is common in older village and tribal rugs, including some Hamadan and very antique Karaja. Experts use it as a clue to age, since rugs made after about the 1930s usually have a cotton foundation, once machine-spun cotton became widely available. Wool's soft, less rigid structure gives the design a fluid, warm character, and the fringes are sometimes braided or in different colors. The drawback is that wool shrinks and stretches with humidity, so these rugs tend to be less straight than cotton-based ones.