Dulux Prepcoat Acrylic Sealer Undercoat is a low odour, low VOC undercoat with excellent hiding power, for use on interior surfaces including plasterboard and textured surfaces. Prepcoat Acrylic Sealer Undercoat features Dulux Ultrasmooth‚Ñ¢ Technology, which helps to eliminate surface imperfections. It is designed to be used under Dulux oil-based and water-based topcoats.