Cotton Surface Ideal for Many Types of Media: Your stretched canvas can be used with a wide variety of artist media, from oil paints and watercolors to acrylic, tempera, and gouache. Sturdily Constructed: These stretched canvas are stretched and stapled onto pinewood bars that create a firm frame. Our canvas painting supplies offer great quality for a great price. Primed & Ready to Go: Each stretched canvas in this set is pre-coated with 8 oz. of acid-free acrylic gesso. So you can start painting and creating as soon as you remove the wrapper.