I use the seal , paint, finish, sand method often. I have also sprayed the board with a sealer to prevent bleeding covered the board with adhesive shelf paper, then carved, then sprayed the letters where the centerline removed the paper. Gives a crisp line. Differing results depending on the paper, some cuts good while some wants to stick to the bit Also smaller letters don't work as well due to center of 'a' & 'e' type letters come off. Capitals work better.
Rick H