When using AirStone as a backsplash, or an outdoor kitchen, we do recommend applying a sealer. Like natural stone, it will absorb grease and food splatters without protection. Use a high-quality brand for concrete, masonry, or porous stone. Follow the manufacturer's directions and reapply as instructed (in general, it's best to apply a THIN coat and let it dry thoroughly before applying another coat). And thanks to Ed and Ann Marie for sharing their Autumn Mountain backsplash photos….nice job!