I've been holding back on commenting on this thread, to see if you had any good results. I've been painting my own instruments for about 17 years, and several times I've seriously tried to make "transparent black" finishes. They all looked awful and got redone. Basically, if the black was transparent enough to see any grain through it, then it wasn't black, but an ugly blueish gray. If the black got dark enough that it looked reasonable, then you couldn't see anything through it. In my experience, I couldn't find anything in between.
Has anyone here actually done a "transparent black" finish, and can show us an example?
There are some alternatives. I've done quite a few basses in opaque gloss black, but leaving the grain not fully filled. So, it's a nice dark black, and you can see the texture of the grain. That's a fairly simple paint job, and a neat look. Opaque satin black over an unfilled grainy wood is also cool looking.
I've seen some other guys do what I call a "reverse grain fill" finish, where the background is opaque black and the grain is filled, over top of the black, with a contrasting color. A trickier finish to do, but stunning looking. I haven't tried it myself, but I think I understand how it's done.
Sometimes those finishes are called "trans black" but they aren't really transparent at all. I'm asking, is there such a thing as a real transparent black finish?