Taking another stab at this, I do not use a clamp with the Mat 1. In fact, I haven't used a clamp since discovering that, for me at least, that silly paper-and-cork Ringmat sounded better on my VPI TNT Mk. II than the recommended mat-less platter and supplied VPI clamp. I couldn't have been more surprised (I had borrowed the Ringmat after being cajoled into trying it). Once I was clamp-free, I decided to see what else was out there and wound up with the Boston Audio which fortunately also sounds the best on my current replinthed Lenco. Dave