Check the size of your 1/2-in. plywood backing board. Then, cut the fiberglass window screen to be eight inches larger than it in both directions (so there are four inches of overhang on each side).

Save the plaster! This might have been the rallying cry of Julia Child, were she a preservationist rather than a chef. “Preserving nice plaster work, if possible, is always worth it,” reBUILD Workshop ...