Natural Stone Sealer with Colour Enhancing Effect Protective impregnating sealer to enhance the colour of Natural Stone Smartseal Indian Sandstone Sealer and Natural Stone Sealer is a high quality, clear, solvent free acrylic impregnating coating system. Application of the sealer will alter the chemical structure of the porous sandstone or natural stone providing a excellent water repellent and stain resistant surface. The sealer, once applied, will give a damp or slightly wet look finish on natural stone and enhance the original colouring of the surface.