Silk is one of the raw materials needed for weaving silk carpets. It is produced by silk worm.
In carpet weaving, use of silk is less than wool and cotton. It is also used, mostly in some carpets of Safavid era as Hunting Design of Vienna Museum.
Warp of some tiny-woven woolen carpets are also of silk, because the weaver could not use short filament cotton, owing to its yarn, and put it on loom, as it has no enough resistance to tolerate the weight of a finished carpet. Sometimes, they use silk for ornamental designs.
Rugs, wholly made of silk, have no applied consumption, but are used for wall decoration, or as a table cloth, ...
Silk, prepared and spun in Iran is used specially in Kashan. There are a few rugs made of silk, because it is hard and cold and is not adequate as floor covering; it is an expensive product and an ornamental carpet.
Silk has various kinds, such as:
1- Raw silk, produced directly out of cocoon and changed to yarn by a special machine or hand wheel.
2- Silk dross, which is gained from the end of filaments, and remaining of cocoon.
3- Head spun silk, is a yarn produced directly from cocoon, spun by hand.
4- Processed silk, which the gum of filament is extracted.
The weight, relatively of warp and weft and pile in woolen or silk carpets, considering type of weaving, are:
Warp: 12 to 20 percent
Weft: 10 to 18 percent
Pile: 50 to 70 percent
As a general rule, could consider that 15% of total weight of a carpet is warp, 15% weft, and the rest belongs to the pile of the carpet.
It has to be noticed, that viscose filaments have a similarity appearance with silk; therefore, some weavers may use those filaments and sell a carpet instead of silk. To distinguish between these two materials, one could steep the yarn, consequently the filaments of viscose tear of easily, but silk filament resist much longer.
To utilize silk adequately in carpet weaving, following process has to be accomplished on silk:
1- "Naghadi": Means opening the skein of raw silk and change it into skein by traditional apparatus, called "Charkh-cheh".
2- "Kubi": Means producing multi-layer silk for utilizing in carpets.
3- "Tadil": Means elevation of number of layers of a silk skein, already prepared by "Kubi".