Martha Stewart Living, October 2004
Using a handsaw and miter box, cut four pieces of corrugated-roofing purlin to fit the outer edge of the picture frame. Be sure to cut through the raised part of the purlin, so that it will meet at the corner.
Cut four more pieces of purlin to create a second frame just inside the first one, cutting the second four pieces so their bumps won't align with those of the outside molding.
Glue two purlin frames to picture frame, matching corners. Let dry. Countersink nails at every other indentation to secure molding. Fill nail holes with wood putty. Let dry; sand flat. Paint; let dry.
Place mirror (that you've had a frame shop cut a "light" 1/16 inch smaller than the frame) in picture frame.