Make sure the appropriate grit is being used. We recommend silicon carbide as it reveals a new cutting edge each time it breaks down into smaller particles; it also creates no static so your substrate and cabinet are free of abrasive material. Aluminum oxide is the economical abrasive option with good cutting ability. No matter which abrasive type you use, make sure you are using the appropriate mesh grit for your substrate: 150, 180, or 220.
-Peter Norman, IKONICS Imaging