Tune your turntables sound with the Pro-Ject Cork it platter mat. The ideal level of damping The idea behind using a cork platter mat is that it delivers the ideal amount of vibration damping. Felt mats can be underdamped, especially when used on metal platters. Thick rubber mats, by contrast, can be overdamped, which can lead to static build-up and more noticeable clicks and pops from the record surface. Cork damps resonances and vibrations more effectively than felt, without the static build-up of a rubber mat.