This the inside end shot showing the curved panel and frame. The frame is typical mortise and tenon, with a routed groove in the rails and stiles to accommodate the raised panel. The 7/8" panel is cut at 18 degrees for 1 1/4" on both front and back and 3/4" of the panel is inside the groove in the frame. This produces a very solid panel. At the edge, the panel insert is 1/4" thick.