599 Enamel Undercoater is a premium interior alkyd primer that is formulated to block tannin stains, have maximum hiding, good filling properties, and outstanding enamel hold out. This product is easy to apply, sands easily, dries to a smooth finish and provides an excellent foundation for enamels. #599 penetrates to protect the wood while providing a sound surface to apply the finish coat, which will give gloss and semi-gloss enamels a slick, uniform finish. #599 may be topcoated with either latex or oil-base coatings.