Masterpiece Artist Canvas 46043 3D PRO 2-1/2" Deep, 20" x 40", Linen&nbsp;12.0oz - 4X - Vintage Acrylic Primed Pure Belgian Linen, 12 oz finished weight. Naturally strong linen, uniform texture. Sized and double primed with archival quality acrylic gesso. Canvas Depth: 2-1/2", Canvas relief: 1/2" (Space between canvas and Bar). Solid Pine or Fir Stretcher Bars from the sustainable forests of the Pacific Northwest. No finger joints are allowed, which tend to fail under pressure and over time. Precision machined double tongue-and-groove corners allow you to increase the canvas tension. Double Wide Brace Included. Bars are slotted on the inside perimeter of the frame to accept cross braces. Patented Keyable Cross Braces allow you to add tension to the middle of the canvas, where it's needed the mostBoth corner keys and brace keys are pre-installed. Stretched using our MuseumWrap method yielding a balanced tension across the surface of the canvas, and a drum-tight stretch that is up to 50% tighter than other methods. Folded corners mean a canvas that is uncut and perfectly intact, allowing the canvas to be removed from the frame and re-stretched.