A jig provides the simplest way to make multiple identical hinge mortises. To begin, make a mortising jig from scrap stock to match your router setup (guide bushing or pattern bit). We used a 1⁄2"-diameter straight bit with a 5⁄8" guide bushing, so our jig cutout measured 1⁄16" greater than the hinge leaf on all three sides to account for the offset between the bit and bushing, as shown far left. If you're using a bearing-guided pattern bit—where the bearing is the same diameter as the bit, shown left—make the cutout the same size as the hinge leaf.Attach the jig to your workpiece with screws where they'll be concealed during final assembly. For project parts where you don't want screw holes, simply secure the mortising jig with clamps or double-faced tape.With the guide bushing mounted in the router's subbase, rout around the jig walls, then clean up the middle with repeated passes as shown in the photo.—from the WOOD® shop