Turntable Mat question

I use a 10" EP and it beats everything I've tried on my slate- plinth Garrard 401.

some audiophiles will use LP Records as a mat

Seriously? This is nuts.
Ever look at a record? The center is thicker.
Ever look at a platter? The center is recessed.
Now why do you suppose that is?
Do I need to paint you a picture?? https://www.youtube.com/watch?v=zxj3xLDNxo0
So ya stack one record atop another, what do you think is gonna happen? Centers be touching, edge be floating. Wafting up and down. Totally unsupported. All outta kilter.

Nuttiest thing I ever heard of.

Saec SS-300 lightweight allow mat or heavier gunmetal Micro Seiki CU180 - this is everything i need for my DD turntables. 

I use Micro Seiki ST-10 Disc Stabilizer on top or my rare Noritake record weight. 

I've never seen anything better that Micro Seiki and SAEC stuff.