Choppers_rule: I would advise you to keep your stippling point very sharp, as your stipple will have a tendency to go from dark to lighter as the tool dulls. Also as Dale Bass says you can grind a four sided stippling tool . Some people say that as light enters the stippled hole it can't come back out with a four sided tool. If your stippling is too shiny then your tool is probably too shiny. I put mine in a battery powered drill and hold it at the appropriate angle as I grind it on a diamond wheel. I use a 200 grit diamond wheel to rough it out then go to a 600 grit. Try to hold the tool at the same angle all the time, as close to vertical as possible.
Denny: I use a one eigth round carbide stippling tool. The tool will dull after a while , so I keep a diamond knife sharpener (flat) handy to dress it up with. All you do is rotate the tool as you are pulling it toward you to resharpen by hand to restore the point. Eventually you will have to resharpen on a diamond wheel with the drill. Unfortunately tools dull with use, but if you want really dark non reflective backgrounds this is what you do. To darken backgrounds even darker you can use Rustoleum flat black paint or as I do it with sharpie black marker pens.
