Scotchbrite is a 3M abrasive product. The most common colors are Red, Grey, Green and White. The color designates the grit of the material. I am blank right now on the actual grits. I think they run about like this: Red = 320, Green = 400, Grey = 600, White = 1000. Someone can clarify those actual numbers, but that should give you a basic idea. I began using scotchbrite instead of sandpaper a few years ago specifically on balls with Mica or glass in the surface. Sandpaper would flatten the particles, where scotchbrite being a softer material will sand around or help remove material from the pores of the ball. I purchase mine from a local auto paint store, in my case a NAPA store. The pieces are larger in size and generally a little cheaper than what I have found at the local WalMart or hardware store. A good paint supply store also normally will have the actual 3M brand, which is a higher grade product. The best way to use any sandpaper or scotchbrite to resurface or add surface to a ball is on a spinner. Remember that according to the ABC any such work must be done evenly to the entire ball. A shame, because there are advantages to scuffing certain tracks to create more grip at a particular part of the balls path to the pocket. The white is my favorite of the materials, since it gives a smooth surface with just a little more bite than a polished ball. Always important to remember that the balls surface is the most important aspect of ball reaction, after all that is what touches the lane. But that is a whole other story.