- Spectralon -- (polyfluoroethylene sintered powder) currently the most preferred material. It is a proprietary material available from Labsphere.
- Matte opal glass -- relatively expensive. Can be used as a diffusing transmitter also. Available as MC-20 from Laurel Industries in Chicago in relatively small pieces (<4") only.
- Magnesium oxide blocks -- (the material is used by athletes on their hands before they do their thing on the rings or high bar). The surface can be renewed with a little scraping if needed.
- Flat white paint -- this is very common. One good choice is Nextel Suede made by Red Spot Paint and Varnish [800-457-3544], but it is expensive (~ $150 per gallon).
- Magnesium smoke -- burn a magnesium ribbon, and let the white soot coat the surface. Burning magnesium can be very dangerous, and the resulting coating is not at all durable.
- Barium sulfate -- available as a powder that may be packed to form a surface. It may also be available as a spray paint. Kodak makes the powder and includes calibration data for the batch. Applied coatings available from Labsphere.
- White Translucent Plexiglas -- Rohm and Haas White Translucent Plexiglas (W-2447) 1/16 inch thick, diffusing transmitter.
