he Tempered Glass Add-on is 10 time harder than regular glass. It has advantages over our standard self-healing PVC mat…It completely stain proof ! Paints, inks and most glues either wash off or razor off with a flat razor-blade. You can cut on it without marking up the surface. It perfectly complements the Glow system when you need a harder, (stain-proof) surface than the standard self-healing mat.