Slip mats. Or should I say grip mats? It certainly seemed like it for years. I've tried all sorts of weird and wonderful combinations of plastics, material and paper. I eventually found drawing office quality tracing paper (pretty much just like wax paper) was good for me under standard black slipmats. Even a 7" single under the mat helped for backspins but scratching stability was terrible. More recently I've been told that IKEA place mats cuts down are good too but I haven't tested that one myself. And won't be either. And of course there's always a Vileda duster...