¾ inches granite slabs or any other natural stones are mostly used for wall veneers. To cover interiors walls such as bathrooms in residential applications and entire offices floors and walls in commercial application. For outdoors ¾ inch natural stone slabs are used mostly to cover building’s facade, or simply the entrance way or the door way of a building. They are manufactured in 3’4 inch thick to save on raw material, since they are not driven over, ¾ of inch thick will have enough strength for slabs to be used as veneers to be cut in very large sizes.
Also this will save on transportation and overall cost of manufacturing and installation. The type of stone determents to what sizes the slabs would be , because granite is very ductile and can be cat in large slabs and the slabs would be still be strong and not brake travertine w or sand stone or any other soft stone can’t be cut in very large slabs unless the thickness of the slabs increases .