Types of Materials
The common materials used in the making of the oriental rugs are wool, cotton, silk and rayon. At times, camelhair, goat-hair and horsehair are used to a very limited extent.
Wool is the most common material used in the oriental rug industry. It is used most often in the pile. However, it may also be occasionally found in warp and/or weft yarns used in the foundation of the rug. Wool's resilience makes it the best choice of material for the making of oriental rugs.
Cotton is the most common material for making weft and warp. It is found, though not as often, in the pile also. It is used in it's natural, undyed form in warp and weft, unless dyed for identification purposes.
Pure silk is the most expensive material used in oriental rugs. Therefore, it is more commonly found in pile than in warp and weft. As well as being the most resilient naturally occurring material, silk provides a luxurious, lustrous look and texture to the rug. It is used to make the most intricately knotted rugs.
Floss silk is a man-made cellulose material often used as imitation-silk. In many parts of the world, it is also called art-silk, not because of it's artistic merit, but because it is artificial silk. Since it's resilience is nowhere close to silk, rayon rugs wear much faster. Thus it bides a collector of oriental rugs to beware of rayon rugs passed by manufacturers or dealers as silk rugs.
Materials are drawn out and twisted together to form yarn and this process is called spinning. The yarn can be twisted in clock-wise direction, also called S-spun, or counter-clock-wise, called Z-spun. For manufacture of rugs, two or three yarns are plied together to make plied yarn. Traditionally done by hand, the process of spinning and plying yarn is mainly done, in today's age of automation, by machines.