are strings of cotton and sometimes wool or silk fibers used as the carpet weft. It should be compatible with other threads used in the carpet in terms of type and diameter and also be delicate and soft to get fixed on the knots and make the carpet flexible. The wool thread used as the weft has special features and is selected depending on other threads used in the carpet. The weft of mattress and other groundsheets is usually made of wool.
- Book Encyclopedia carpets from Iran, Mr. Ahmad Daneshgar