re: Ten Commandments

I probably should seal, but I don't. I sand to 320G and because I engrave 2-3 times, I get enough depth to keep it relatively clean.
I try to keep away from grainy wood, though at times the affect can be quite pleasant.  Probably a coat of sanding sealer (shellac diluted 1:10 with metho wouldn't hurt).

Sometimes I use tape (special laser tape... not cheap, but in bulk it's much, much cheaper than masking tape.  The problem is that you need to sand quite a bit to remove the tape after it's been backfilled.  Couple of videos I made,

I only use Timbermate (with colour) for engrave infills or leave void... never paint... Splinter is the "ejncyclopidi" with 'poxies and other media.