Today rugs can be made from many various types of fibers, some natural, others synthetic. Each has its benefits.
Cotton fibers form within the cotton boll or the seed pod. Once processed and spun, cotton fibers are soft and lightweight, quick to absorb and quick to dry. Cotton can be used as a binding thread to help form the backing and fringes found in area rugs, or it can also be used as the body or main fabric in some area rugs.
Rayon starts as a natural product – cellulose - found in the walls of all plant cells. Spun rayon is very much like silk and was known for many years as artificial silk. Production involves collecting wood chips and putting them through several chemical processes that eventually yields viscose. The viscose is pushed through a spinneret, a metal plate with many small holes. The viscose strands shoot out of the spinneret into an acid bath where they harden into fibers. The size of the holes in a spinneret determines the thickness of the fiber.
Nylon is a man-made material, the raw materials of which are petroleum, natural gas, air, and water. Combined by chemical processes into long-chain polymers, the result is the fiber-forming substance known as polyamide, which is melted, spun and drawn after cooling to create a fiber suitable for floor covering. Nylon rugs are extremely durable and stain resistant.
Polyester is a synthetic fiber, widely used to make products ranging from carpets and clothing to park benches and milk bottles. Polyester has a luxurious feel when used in rugs and excellent color qualities; it’s resistant to water-soluble stains and easily cleaned. When used in thick, dense cut pile Saxony or textured styles, it's an excellent value with outstanding performance characteristics.
Polypropylene or Olefin
Polypropylene fiber is a petroleum products, characterized by its resistance to moisture. It is strong, abrasion-resistant, quick drying, colorfast, mildew-resistant, and soil- and stain-resistant and lightweight. Polypropylene is inexpensive and due to its lightweight nature, not very durable.
Wool is a natural product with remarkable characteristics -- fiber elasticity that can stretch up to 40% and rebound, a waxy outer membrane that covers the fiber's core, keeping water from penetrating easily, and a scaly texture that keeps soil particles on the surface of the fiber, making them easy to vacuum . Wool naturally resists mildew, mold, and fungus attack in almost every climate. Yet with all that, rugs made of wool offer a soft feel with outstanding durability and can be created in a variety of strong or subtle hues.
Silk is a natural product, spun from the cocoons of the silkworm. It is versatile, absorbs moisture, and has a smooth, polished texture. While it can be dyed easily, it also stains easily and has relatively poor resistance to sunlight exposure, and may be subject to fading. Silk, while seeming thin, is the strongest natural fiber and is lustrous. Rugs made of silk can be very expensive because the material itself is expensive, and the very nature of that natural material requires an extraordinarily high number of knots per square inch (1,000/Square Inch or more) - far more than wool or cotton rugs.