This shade sail is made out of some strong material,  I actually looked it up.  It is made of High-Density Polyethylene and is as strong if not stronger and more stable than some plastics, wood, and even metal and it does not rust. The material is safe,  has no harmful effects at all!!!  It can stand weather from all year. I highly recommend this shade, it protects you from the harmful sun rays and keeps you dry while working on something or just setting under it. I HIGHLY RECOMMEND THIS SHADE SAIL,  THE MATERIAL IS STRONG AND LASTS FOREVER!  (www.scrantonproducts.com) This site tells you everything you need to know about this material and it is the best material that I have bought. When I have it set up, will definitely post again!