Abstract: An attachment (10) to facilitate precise cutting of a sheet of inlay material (26) with a router (12) to fit a cutout in a sheet of underlying material (28) comprises a top plate (30) and a spaced-apart bottom plate (32) defining a slot (34) for receiving the sheet of inlay material to be cut. The router (12) is mounted in a collar (42) adjustably secured to the top plate (30) over a clearance hole (40). A rotatable cam (76) is mounted in the bottom plate (32) beneath the clearance opening (40) in the top plate (30). The rotatable cam (76) includes an offset depending cam follower (78) which follows the edge of the cutout in the sheet of underlying material (28) so that a matching edge can be cut in the sheet of inlay material (26) for precise patching and inlay work.