Proline Decorative Concrete Systems RS180 54" x 31" Castle Stone Concrete Stamp. This stunning pattern is a single tool application. As with all Proline patterns, this pattern also comes in a thin-flex mat for finishing edges and stamping against walls. Stones, ranging in size from 9 Inch x 12 Inch to 13.5 Inch x 22.5 Inch, have hammered edges and defined grout lines for a more natural and random look. Prolines Bluestone Texture accents the background of this eye-catching piece. With Prolines help, you can transform this relic of the past into a modern-day masterpiece.