Thickness of stone veneer sheets is 1 mm to 3.5 mm this is because of natural 3 dimensional surface of real stone. We actually split or pull the slate into very thin layers of stone and apply Glass fiber reinforced polyester resin (GRP) under extreme pressure and heat for a strong bond producing the backing for stone veneer sheets. Due to high degree of adhesion accomplished between the slate and GRP product now becomes flexible to an extent.