Olefin works best in berber styles, is durable against abrasions, is easy to clean and more resistant to moisture and mildew. It is usually the most inexpensive fiber available. However, olefin can have a tendency to crush more so it just has to be in it's proper location. Polyester is durable against abrasions, easy to clean, and typically costs less than nylon and wool. Some styles are made from recycled plastic bottles, which is a great environmentally friendly perk. Polyester does not hold its fiber height under heavy traffic as well as other fibers. Nylon is the most popular fiber. It has consistent quality, durability and softness and can offer more colors than other fibers. Most stains can come out easily with your own spotter or a professional cleaner's services. Because of the nylons high quality, it tends to be on the higher end for price. SmartStrand® is exclusively Mohawk's fiber that was introduced in the last 10 years. It's the best of both worlds of nylon and polyester and is a polymer composition with superior durability and softness. SmartStrand®has a lifetime stain and soil resistance that is built into the fiber and doesn't wash off with cleaning. It is eco-friendly offering styles that are made with renewable resources like corn and is usually less expensive than nylon.