Martha Stewart Collection Bamboo Cutting Board, 14" x 20" . $29.99. natural long-grain bamboo cutting board. Marth Stewart. Won't dull your knives. Natural materials not only lend a charming, rustic air to your countertop, they're also gentle on your knife edges. This cultured cutting board is finely crafted from natural long-grain bamboo - both lightweight and exceptionally tough - for perfect prep and protection. Limited lifetime warranty.