I have a rental property in Seattle I wanted to put artificial turf into. One of my neighbors has artificial turf and his turf is Nylon. It is very rough, course and dark and I don't think it looks natural at all. I did my home work online and found a great article on Global Syn Turf.com It talks about Nylon vs. Polypropylene synthetic turf fibers. It says the first synthetic turf fibers were actually made from nylon, such as in the astrodome. Nylon is very tough and very expensive material in production and is highly resilient to foot traffic. However most artificial turf today is made with Polypropylene thermoplastic blended with Polyethylene thatching. They said an invention of polypropylene is the reason synthetic turf is available for yards today. Polypropylene is a non corrosive, rugged and resistant to most solvents, bases and acid polymers. I spoke with someone on the phone who further educated me that colorants and additives can be introduced during the extrusion process to create distinct colors and properties such a stabilization against ultraviolet light degradation. The artificial turf will no fade over time which makes it great for outdoor landscape use. This product can be used in extreme temperature like heat and cold. The artificial turf only looses 10% of its strength over time. I ended up ordering samples from Global Syn Turf and could not believe how realistic the artificial turf looks. I ended up buying 1,000 sq. ft. from the Global Syn Turf dealer here in Seattle and installed it myself. It looks great and much better than my neighbors nylon artificial turf yard.