Stamped Concrete It is concrete that is imprinted with shapes and patterns before it fully hardens to resemble: Natural stone. Brick. Tiles. Wood. Common Specifications: Slab thickness: 10–15 cm for walkways and yards. Concrete strength: 25–35 megapascals or as per design. Adding a surface colorant or integral color. Applying a release agent before stamping. Stamping the surface with special molds. Applying a sealer after drying.