Gunther Prime-N-Seal is a superior, quick drying acrylic primer and sealer designed to help eliminate mirror installation failure. It enhances the adhesion of mastics while protecting the mirror from substrate contaminates. Prime-N-Seal promotes exceptional adhesion to drywall, green board, cement, plaster, plywood, brick, and other substrates. It does not become brittle with age, is non-flammable, and does not contain environmentally damaging ingredients. Easy-to-apply by brush, roller or spray. Flat white appearance when dry.