A finished canvas tray float frame, showing the 1/4" gap around the canvas. It is worth pointing out that framing canvases in this way can often be troublesome. Even high quality stretcher bars can be unsquare, this means that measuring the canvas along the edges will appear to give the same dimensions on each side, but the measurement from diagonal corners will show if the bars are square or not. Canvases will also often be slightly narrower in the middle compared to the edges.
The cheaper canvases favoured by many artists are often dramatically unsquare, and even warping in each bar can mean the canvas won't lay level on a flat service.
