The stretched canvas is a high-quality, economically priced canvas with a staple-free, 3/4" deep profile and key-able corners that allow for tension adjustments. It is stretched using a premium grade 7 oz. acrylic primed cotton canvas, and Masterpiece's MasterWrap technology. It features a drum-tight, archival surface that works great for both oil and acrylic paints. The solid, finger-joint free, kiln-dried bars are milled with lumber and harvested from sustainable forests in both Oregon and California.