Yarn is one of the most important elements of a carpet. It is produced of cotton. Yarn, comparing to wool, is much better, because it has less flexibility and gets no wrinkle when left uneven and un-smooth, results no spongy or porous, and also carpet stays fit on the floor.

Hand-spun yarn is only used for warp and weft of low priced carpets and rugs which are produced in villages. Thick wefts of some tiny woven carpets, produced in big cities and big villages, are utilized with the same yarn. For this purpose, the hand-spun yarn is better than machine-spun. It is less expensive and its packing is easier.

In past, machine-spun yarn was produced mostly from India and imported to other countries; but recently spinning workshops for yarn are established in many countries; i.e., in Isfahan, Yazd, Kashan, Tabriz, Qazvin and Mazandaran (Iran). Nowadays. cotton used in carpet weaving in Iran, is produced inside the country and is offered by spinning internal factories as yarn. This yarn is not as desired as imported yarn, but is acceptable in quality.

Machine-spun yarn is used for thin and fine warps and wefts on the urban and semi-rustic carpets. Yarn is graded as wool; the higher grade appropriates to the thicker yarn.

In past, there were yarns thinner than 9 layers, but now it is substituted by silk. Yarn number 20 is mostly used. Yarns utilized in carpet weaving and also graded in connection with wale-counting are as follows:

Yarn grading, contrary to wool, is according to thickness of the yarn; the higher number shows the better yarn, ordinary consists of 24 layers, 12 and 9 layers (24 is thicker than all).