No mat on the Clearaudio, FWIW and I'm no expert, I've been told by the technician who helped me setting it up that there is no need to use a mat as the platter is made of a high density material (Polyoxymethylene, POM) that doesn't generate any vibrations, and the chassis is supposed to be designed in a way to keep resonances out of the audible range
But I still have somewhere a Ringmat as well as cork mart (which I got from Disk Union in Tokyo during my last trip to Japan), I'll give those a try to see if they can improve the sound in any way
