Believe it or not, this can be done with an ordinary pencil and a can of jeweler's rougue. Set the drill press to a slow speed, chuck in the pencil eraser down, smear on a little jeweler's rouge and go to town. The tricky part is keeping the pattern consistant. Be sure to practice first on some scrap metal. That way you can get the speed and amount of pressure you need to get what the result you want.