Mmm... I cannot see this turning out to be inexpensive enough for many. Perhaps another approach would be to use a black acrylic undercoat, with spray polyurethane on top, rubbed smooth after 2 coats. It will build faster, and give a nice glossy finish with less fuss -- even available in spray cans for "DO try this at home, folks"..

But for the 1-5 purists.. piano black laquer will be the ultimate.

Cheers