The material being used in a carpet determines the final result of the carpet and how it grows old. The most commonly used material is sheep wool, although other materials may also be used.
Wool is gathered from the flock of sheep and is used for the pile, warp and weft.
Cotton is grown in most carpet producing countries, and is often used in the warp and the threads for the weft.
Goat hair is not being used for the pile nowadays, it is mostly used in the warp, weft and for the sides in, for example, Beluch carpets.
Silk is used in the warp, weft and the pile in more exclusive carpets. The fine threads are gathered from the larvas of the silk butterfly.