One of the things that I have been trying to figure out how to do is inlay shell in a straight channel, like jewelery box lid. Sounds simple, but it is a challenge.
What I used is:
1) The tiny Dremel router bits from StewMac, PN 1180. And Dremel with Router base. You will also need the 3/16" collet.
2) A strip of purfling, in this case maple, from LMII, PN PF1. The strip is 1mm thick.
3) A 1/16" chisel. In this case from JapanWoodWorker, PN 14.300.015
4) Some 2.5mm wide shell from LMII, in this case the laminate.
5) The Dremel is tapered, not straight. This means that the shell will fit pretty tightly. So what I did is take the Dremel out of the router base and used the same bit to clean up the channel, almost creating a bit of overhang.
Adjust the Dremel so that the bit extends only as deep as the shell inlay. Make the first cut using the Dremel. Then make a second cut using two pieces of the purfling as a spacer. In both cases, using a straight edge. Then use the chisel, GENTLY, to knock out the center strip that you don't want. GENTLY. The strip will come out mostly at the same depth as the two side cuts.
If you do this gently and slowly, there will be no tear out along the sides of the channel.
Take care,
Guitar Ed