A black background works great for me. The trick is to use a sheet of black velvet. Be sure to position your light to bounce off the ceiling directly overhead (will need a flash gun either mounted on camera with a swivel bounce head, or a flash off camera via cable, or wireless). If you position the light at right angles to the fabric, you will get a sea of white dots as each tip of the velvet will somehow reflect a small amount of light back.
