Sealing stone is strongly suggested, as it will create a barrier between the stone and dirt and stains. Even if a sealer is used, this is NOT going to make the stone 100% resistant to stains. Any staining agent that comes into contact with the stone should be removed immediately. Sealant and cleaner should be included on every stone order. We sell the Miracle Sealant Company products because they are widely considered the best available. Sealant is easy to apply. Use a sponge brush, paintbrush, or roller to spread it evenly over the surface of the stone. Traffic and use will affect the need to reseal a surface but resealing annually is a safe time frame.