Fredrix Value Series Canvas is a Medium Texture polycotton stretched artist canvas that is back stapled. Each canvas is Acid Free - Archival Quality acid-free acrylic titanium gesso primed. Primed weight varies from 7 oz - 12 oz. The stretcher bars are Gallery Style 1-1/2 in. x 11/16 in., and are Kiln dried to prevent warping. Ready for use with oils or acrylics.