Turntable mats are thin, disc-shaped objects that users place upon the turntable platter before playing a record. They can reduce vibration, help to maintain constant rpm, and even protect the platter surface from unwanted damage. Different materials are used in the manufacture of these mats, and each material can have advantages and disadvantages.
Cork, for example, is non-resonant, works well on steel and lightweight platters, and does not over-dampen the turntable like felt can. Cork also helps with vibration control and can provide some sound enhancement.
Another popular platter mat is wool. This is soft, does not increase bumps on records, and can be folded flat to fit on the turntable. It can, however, collect dust, so it is a good idea to keep the mat covered when not in use.
Other manufacturers make platter mats from a variety of materials, including leather, suede, and various types of wood. These mats can be a bit expensive, but they offer a more natural and pleasing sound than the standard black rubber found on most turntables.
Choosing a platter mat can be a game of trial and error, so try different ones to find out which one sounds best for your system. A little experimentation is fun and can lead to an improvement in the resolution (clarity) and sonic impact of your vinyl playback system. Changing the mats can also change the resonant characteristics of your turntable, which will have an effect on how your cartridge pulls the music from the grooves.