Dulux 1Step Prep is your first step toward a superior long-lasting paint finish. With mould resistance and stain blocking of tannin and flash rust, Dulux 1Step Prep ensures your interior or exterior paint shines now and into the future. Use Dulux 1Step Prep for all paintable surfaces around the home including interior and exterior walls, ceilings, trim, doors, windows and especially where mould is a problem including kitchens, bathrooms and outside areas. Suitable for use on interior and exterior surfaces including paperfaced plasterboard, timber, MDF, brick, render, masonry, concrete, cement sheet, Zincalume, galvanised iron, PVC and previously painted surfaces. For set plaster, use Dulux Precision Sealer Binder.