My original panel holders used a narrow slot to hold the 1/8″ thick panels in place. My stretched canvases are 7/8″ deep so I used a different design with a thin lip of lath to hold the canvas in place. In this photo, I’ve just glued and clamped a piece of 1 1/8″ lath to a piece of 1″ x 1″ stock. Once the glue dries, I will drill holes on the right side for the magnets.