What makes indoor-outdoor fabrics water resistant?These textiles are woven from synthetic materials such as acrylic and polyester, natural fibers such as cotton or a combination of the two. They're treated with a chemical coating that wards off water and stains, as well as protects against mold, mildew and fading from UV light rays. This makes them ideal for moisture-prone spaces such as bathrooms, basements and laundry areas, as well as rooms that get a lot of sun.