The art of carpet weaving has existed in Iran since ancient times. This is proven by the 2500-year-old Pazyryk carpet, dating back to 500 B.C., during back to the Achaemenid period.
The first documented evidence on the existence of Persian carpets came from Chinese texts dating back to the Sassanid period (224 - 641 AD).
This art underwent many changes in various eras of the Iranian history to an extent that it passed an upward trend before the Islamic era until the Mongol invasion of Iran. After the invasion, the art began to grow again during the Timurid and Ilkhanid dynasties.
Over time the materials used in carpets, including wool, silk and cotton, will decay. Therefore archaeologists are rarely able to make any particularly useful discoveries during archaeological excavations. What has remained from early times as evidence of carpet-weaving is nothing more than a few pieces of worn-out carpets. Such fragments do not help very much in recognizing the carpet-weaving characteristics of pre-Seljuk period (13th and 14th centuries AD) in Persia.
The weaving of pile rugs is a difficult and tedious process which, depending on the quality and size of the rug, may take anywhere from a few months to several years to complete.
To begin making a rug, one needs a foundation consisting of warps strong, thick threads of cotton, wool or silk which run the length of the rug and wefts similar threads which pass under and over the warps from one side to the other. The warps on either side of the rug are normally combined into one or more cables of varying thickness that are overcast to form the selvedge.
Weaving normally begins by passing a number of wefts through the bottom warp to form a base to start from. Loosely piled knots of dyed wool or silk are then tied around consecutive sets of adjacent warps to create the intricate patterns in the rug. As more rows are tied to the foundation, these knots become the pile of the rug. Between each row of knots, one or more shots of weft are passed to tightly pack down and secure the rows.
Depending on the fineness of the weave, the quality of the materials and the expertise of the weavers, the knot count of a hand made rug can vary anywhere from 16 to 550 knots per square inch.
When the rug is completed, the warp ends form the fringes that may be weft-faced, braided, tasseled, or secured in some other manner.