Proline Decorative Concrete Systems RS300C 52" x 36" Arizona Flagstone C Concrete Stamp. Arizona Flagstone, one of our "Signature" pieces, offers the realistic look of Flagstone with the durability and low cost of concrete. This is one of the stamps that has made Proline a leader in the decorative concrete world. This lovely pattern will compliment driveways, walkways and patios with its natural beauty. This pattern consists of a 3 separate stamps, allowing for random placement of stone.