Shasta is Masterpiece's heaviest weight surface. The 14.5 oz. raw cotton canvas is sized and triple primed, giving it a 20 oz. finished weight. This super rugged canvas is designed to have a substantial tooth that makes it suitable for heavy paint applications and aggressive painting techniques, which apply significant pressure on the surface. It is ideal for artists who prefer a very strong and durable painting surface on a large size canvas. The canvas surface is highly absorbent and works well with oil and acrylic paints. It is both acid free and pH balanced.