Glue the butterflies
Cut the corners of the recess with a chisel or
knife. They’ll be rounded after routing, but they
must be cut to acute angles so the inlay fits.
Spread a thin layer of glue in the recess, put in
the inlay, scrape off any glue squeeze-out, and
cover the inlay with a small piece of white
paper. Clamp a thick board over the inlay and
let the glue dry. The paper will absorb any
further glue squeeze-out. After the glue dries,
remove stuck pieces of paper by lightly wetting
them. Level the inlay with a block plane or by
scraping and sanding.