I bury laser-printed decals in lacquer headstock finishes that turn out pretty good...
You need to put a thin finish on the face (just a couple coats) and sand it back fairly fine so you have a flat, non-porous surface for the decal to adhere to. 400 grit is fine enough.
Clean the surface with naphtha, apply the decal, and give it plenty of time to dry - you don't want any moisture under the succeeding coats of finish. So... 24 hours or so.
A fine mist finish over that, to seal the toner so it doesn't melt and get fuzzy-looking from exposure to acetone. Toner is actually super-fine plastic powder, so it'll melt in the presence of acetone if it's wet too long.
Once that's well-dry, you can start putting cover coats on the whole face. Figure 3 or 4 at least.
Using a flat sanding block, sand over the decal area only, clean it off with naphtha, and shoot it again.
Repeat 3 or 4 times, about an hour between coats. This has the effect of raising the surface around the decal while maintaining the decal's height. At that point, it should appear that there are no edges to the decal. If there are, a few more shoot/sand cycles should finally level it.
Once it's level, a couple/few more cover coats for good measure, then let it sit for a couple weeks.
Level and finish sand, buff out with compound, and polish. Viola! Buried headstock decal!