Polyester is a good compromise between nylon and thicker natural fabrics. Even tightly woven, it is still very light weight. Polyester curtains do not tend to fade the way that other natural fabrics do, and they are usually machine washable. They can be lined to make them heavier and to block out even more light, and they are generally quite stain resistant too. Being stronger and more resistant to chemicals, they have a much longer product lifecycle meaning they have to be replace less frequently. Being recyclable, it also requires less water and less energy to dry as compared to other fibers