Router inlay templates

1. Draw the inlay shape once and save it as an SVG.
2. On the workbench, choose Cut a hole and download the template. This is the pocket: the hole in the base matches the drawing.
3. Switch to Cut out a piece, keep the same size, bushing and bit, and download again. This is the insert: the part that falls out matches the drawing.

With a 5/16 in bushing and a 1/8 in bit, the pocket template grows by 3/32 in and the insert template by 7/32 in. The offset calculator works out any other pair.

This does the same job as a brass inlay kit, where a removable collar adds one bit diameter to the bushing. With two templates you need only the bushing, and the insert can be any shape you can draw.

A round bit can't cut a sharp inside corner. In the pocket, every point of the drawing (like the tips of a star) comes out rounded to the bit's radius. On the insert those same tips stay sharp, so they won't drop in.

Round the outward points of your drawing to at least the bit's radius before you make either template: 1/16 in for a 1/8 in bit. Then pocket and insert match. The drawing's inward corners take care of themselves: sharp in the pocket, rounded on the insert, which leaves a tiny gap the glue fills.

Small bits give crisper inlays. Use the smallest bit your bushing and stock allow.