What is Cotton in Oriental & Persian Rugs?
Rug Materials: What is Cotton?
City carpets are usually woven on a cotton foundation except for occasional use of silk. Tribal and village rugs may have a wool foundation but it would be extremely difficult to achieve the standards expected in a workshop carpet with a wool foundation. Put simply wool bends and stretches. This is excellent for pile but not for the foundation that is to hold the intricacies of an Iranian city design.
It is tempting at times to suggest that older carpets have wool foundations and that later rugs use cotton. While in individual cases this may at times be true such as with the Turkmen it does not hold up against the broad category of Oriental rugs. Virtually all extant rugs today date to no earlier than 1500 AD. The best of the workshop rugs as back as far as we have examples use cotton or silk foundations.
The Incidence Of High Ply Counts In Early Cotton Warps
It is tempting at times to suggest that older carpets have wool foundations and that later rugs use cotton. While in individual cases this may at times be true such as with the Turkmen it does not hold up against the broad category of Oriental rugs. Virtually all extant rugs today date to no earlier than 1500 AD. The best of the workshop rugs as back as far as we have examples use cotton or silk foundations.
Times a fiber may be bent over upon it self before it breaks:
Sea Island Cotton 3,200
Silk 1,800
Rayon 75
Wool over 20,000
As we can see from the chart to the left cotton is not as resilient to bending as wool. However cotton is an ideal fiber for warp and weft because they are not subjected to the bending that pile is subjected to in use.
Notes: Sea Island cotton is one of the best grades of cotton. It is a long staple (fiber) cotton that would hold up better that the cotton used in most rugs.
Test Method: Burn a small amount of the fiber. Cotton smells like burning paper and silk smells like hair. Petroleum based man-made fibers can have a variety of odors when burnt but the key to identification is that they melt and burn leaving a hard bead residue.