turntable mats: should I use one?

I posted this a while back and it may be useful:
This

Dear Moonglum, Unfortunate many or maybe most LPs are not perfectly flat.
Using Reso-Mat for a convex LP there are only the 3 inner points contacting record. The grooved area, actually the whole record is spinning in air.
The other side is concave and thus there are 6 outer points in contact. This case is sorted out with light clamping and thus all points are in contact.
Sonically both cases may very well benefit from light clamping. On the other hand too heavy clamping ruins everything in achieved sound improvement. I use clamp only for flattening concave LPs.
In my system Reso-Mat, and particularly tall Reso-Mat improves sound quality and quantity in all frequencies, and with all records. After 2 years I have not experienced sibilance nor other issues caused by Reso-Mat. I have one "top" MM that suffers from annoying sibilance, even with new stylus (a false sample or a false "god").
In my system lifting record off the platter seriously improves the sound. Music just flows nicely. For me there´s no turning back to conventionl mats.
I must point out that I still use the original dense and soft mat (GROOVE ISOLATOR) under Reso-Mat because it eliminates ringing of the metal platter.

Has anyone tried a cork mat? Theoretically, cork should be excellent as a material as it is a natural vibration control material. I imagine natural musician's cork 1/8" thickness would be the cat's pajamas.

Hi Harold,
There are qualities about the Resomat that I like. Sibilance is not what I'd describe as excessive, just a whisker more than I'm accustomed to. On the face of it both mats are unconventional being mostly suspended in air. It's obviously a synergy issue because many who use similar T/Ts - with the heavy mat as an underlay for platter damping - are reporting good success.

Kind regards,

Hi Geoff,
Good point. Full sized cork mats are widely renowned as having desirable sonic properties and some manufacturers just install cork mats on the platter as default even to the extent of bonding them on permanently.

Of course, that just takes away all the fun.... :^)
Cheers,