I used Varathane ebony stain. It results in an excellent, matte black color but I found that it never seems to fully dry as advertised (or perhaps it will in a few weeks). The stain was constantly rubbing off on my fingers and making a mess. A simple solution was to spray each piece with a thin layer of lacquer, which effectively sealed the surface. Note that I did try thin coats (wiping the stain off after a few minutes) but for whatever reason, this stain does not want to evenly penetrate the wood.