Quality matters in stretcher bars since to maintain paintings from warping. This stretcher bar comes from high quality pine molded with finger splicing. Finger splicing bonds wood pieces in such a way to make the bars long and straight as possible. The innovative curved back edging prevents blotting impressions on the canvas once mounted. Interlocking corners slide together and lock in 90 degree angles. Cross bracing adds further support making the framework and painting last for years to come. Stretcher bars come with corner key wedges. Wedging fits in the slot on inside corners of the assembled framework. If a canvas does sag due to stretching then wedging driven into the corners expand the frame slightly, and the canvas becomes taunt once more.