Wool
Wool fiber is produced from the fleece of lambs or sheep. Wool is imported from countries such as England, Australia, and New Zealand. Wool is the oldest and considered to be the finest of all rug material.
The ability of wool to stretch up to 40% of its original length and the fact that it can be bent back and forth more than 180,000 times without breaking makes it very resilient. Wool is the most expensive material for rugs, although it is also the best you can buy.
Silk
The fiber of silk is produced by the larva of various insects known as silk worms. The silk, in continuous lengths from 300 to 1600 yards is spun to produce the cocoons. As a fiber, silk is naturally non flammable, strong, and not affected by static charge problems - even at low humidity.
Cellulose fiber
This type of fiber is produced by plants and normally not used as face yarns. These types will however, show up as backing materials of tufted as well as rugs that have been woven.
Cotton
Cotton is a vegetable seed fiber that is produced from the cotton plant. The primary use for this fiber is yarns woven in rugs. Cotton is resistant to alkaline solutions and becomes stronger when it is wet.
The biggest disadvantages to cotton is the fact that is the most absorbent of all fibers and requires extended drying times after being wet cleaned. It is also easily damaged by acids, stains easily, mats down, soils quickly, and is subject to mildew, dry rot, and shrinkage.
Jute
The fiber of jute is produced by the jute plant which grows in South America, Pakistan, and even in India. The stalk of the jute plant is where the longer coarse fibers are obtained, located between the outer bark and within the inner pulp.
Jute is normally used as weft yarns, across the width, in woven rugs and as a backing material in the construction of tufted rugs. Jute is an inexpensive material that also serves other uses than just rug. Like all other fibers, this one has disadvantages as well. The fiber is weak when it becomes wet and is also subject to dry rot, shrinkage, and mildew.
Sisal
The fiber of sisal is produced by the leaves of the agave plant. Sisal is very strong and primarily used for making rugs, sacking, rope, and even rug. The fiber stains easily and makes for a difficult rug cleaning process. Wet cleaning can also cause shrinkage so it's best to use low moisture methods.
Rayon
There is quite a bit of confusion about rayon and it is easy to understand why. Rayon is a synthetic fiber that is produced from natural cellulosic fibers of wood pulp or cotton. The material is put through several chemical treatments which help to turn it into a synthetic fiber.
Primarily, rayon is used for area rugs because of its silk like appearance. It can be damaged by acids, has low resistance to abrasion and is also prone to cellulose browning.Area rug repair requires special techniques by professionals to restore it to its original state.