I too made my board out of plywood - 1/2 inch ply with two 1 inch moulding strips to hold it onto the old metal ironing board. I covered it with a layer of mylar, two layers of warm & natural, and used canvas as my cover. After stapling everything tight, I used a spray bottle of HOT water to shrink the canvas. Worked great. Then I used a straight edge and marked the top (micron pigment pen): three straight lines the length of the board (48inches) and several lines perpendicular so that Icould press/iron my selvege edges straigh (one on the right side of the board and the others at 42, 44, and46 inches. These measurements have sure made ironing yardage a lot easier and finding the straight grain is also a lot easier.