For centuries, wool has been used in the making of the finest area rugs for some very good reasons. 
Wool is the softest, most luxurious of fibers. It is inherently stain and soil resistant in addition to being exceptionally resilient (bounces back after repeated crushing). 
Wool is also flame retardant (will not support combustion) and will acclimate itself to the environment (when a room is too humid, wool absorbs excess humidity. The reverse is true when the room is too dry!). 
As a natural fiber, wool is environmentally friendly and totally bio-degradable. Unlike man-made fibers that must be subjected to various stages of crimping and processing in order to achieve certain characteristics and styling choices, wool's natural crimping characteristics and soft luster allows it to be fashioned into many colorful textures and beautiful styles. 
When comparing costs to man-made fibers, wool is initially more expensive. However, when you factor in the longevity and durability, let alone the luxury factor, wool becomes much more affordable, and may even cost less in the long run. 
Wool is produced in many parts of the world. The most famous for it's softness, length, and clarity is Decorwool (registered trade mark) from NewZealand. 
Other wools such as wools from England and Scotland are also well regarded among other wool producers. 
Wool is fashioned into many styles (residential & commercial) with many textures, patterns, and manufacturing methods for wall to wall applications and area rugs. We feature a large selection of the world's finest wools, come see us to select your own.

Nylon is man's finest achievement to date in creating an alternative man-made yarn with outstanding performance characteristics. 
There are many types of Nylon available, the most common are type 6, and type 6.6. Type 6 Nylon is currently produced by BASF® and Allied Signal®. Type 6.6 is produced by Dupont® and Solutia ® (formerly Monsanto). 
The molecular structure of-the two types is different and so is performance. We feel that type 6.6 Nylon is superior in terms of fading, and overall wear characteristics. 
Generic Nylons are also available (unbranded), however, it is advisable to stick with branded fibers that insure consistent quality, performance and warranty coverage. With branded Nylon, your warranty is also backed by the fiber producer which is much more comforting to know than if only backed by the mill. 
When a Nylon is branded, such as Dupont Staimaster®, or Solutia Wear-Dated®. It must meet the rigid requirements of the yarn producer including static control and texture retention to be classified as Stainmaster® or Wear-Dated®, which insures that you, the consumer, are getting the quality you had bargained for. There are also several grades, within the branded yarns depending on the look and "feel" you desire from the inexpensive to the moderate or higher price range. 
Nylon offers great resilience and resistance to soil and stains when treated properly (which goes back to buying branded vs. unbranded carpet). 
We believe that Branded Nylon, type 6.6 (Dupont Stainmaster® or Solutia Wear-Dated®) offers the best overall value and performance. We feature a great selection of the finest Nylon carpets available. Come see us.

Polyester has been used in clothing, drapery, carpeting and other fabrics as well as in resin form for various uses. 
It has good properties such as resistance to stains and depth of color absorption. 
In the early years of Polyester carpeting, the fiber was used in "Singles" and not plied for strength causing rapid wear and overall weakness. 
Even though the methods of manufacturing have improved a great deal since then, the fiber is still plagued with other purchase- deterring characteristics. The fiber's weak points are primarily lack of sufficient resiliency (packs down). Filling, fuzzing, or "Shedding" result from the fact that the fiber is made in "short staple format" and not long staple or continuous filament. In addition, the fiber has excessive luster, which when made into carpeting results in a "plastic look" to the carpeting thus affecting the overall look which diminishes appeal. 
Nylon on the other hand is more versatile and is therefore a better choice in man-made fibers. 

Olefin has been produced for a number of years in manufacturing inexpensive commercial level loop carpeting. In recent years, however, many Berber styles of carpeting have been made with this fiber due to the fiber's low cost and ability to resist stains (from spills). This fact has been greatly oversold and has resulted in many unhappy consumers nationwide for the following reasons: 

1- Even though Olefin is stain resistant, it is Not stain proof! 
2- Olefin will soil (a condition caused by tracking dirt onto the surface of the carpet, and when soiled, is hard to clean. 
3- Olefin lacks resiliency, and therefore, the fiber will matt down, crush and pack. 
4- Olefin has a very low melting point (heat generated by rubbing the side of one's shoe is sufficient to melt the yarn in that area)!
We generally recommend Nylon or Wool instead of Olefin because we feel that the other fibers offer a far better value than Olefin.

*Acrylic/ Acrylic blends
Rarely used alone, it is blended primarily with Nylons for strength resulting in a soft hand and wool-like luster. However, Acrylic is brittle and has tendencies to break in addition to being less resilient. Stain and soil resistance properties differ with the percentage of the blend as in 20%/80%, etc.

*Cotton
A lot of cotton wall-to-wall carpeting was made in the 50's. The fiber was very soft and it accepted dyes well resulting in soft pastel colors and rich jewel tones common to natural fibers, but lacked resiliency and stain resistance. Currently, few manufacturers offer cotton carpeting, but it is still widely used in bath mats and many other fabrics. 

* Sisal, Coir, Jute, and Seagrass are described separately under "Natural Fibers".