Prime-it Plus is a premium quality water-based stain-blocking primer-sealer. It adheres firmly onto glossy, chalky, and other difficult surfaces to provide an excellent undercoat. Prime-it Plus provides exceptional stain-blocking and bleed-through resistance from water stains, smoke damage, grease stains, graffiti, cedar, redwood and plywood bleed. As a universal primer it can be used under latex or oil-based paints. Prime-it Plus is recommended for both interior and exterior applications.