As a water-based base coating specialised for interior & exterior wood surface, Dulux Stain Block Sealer contains unique oil-blocking components, allowing it to cover and inhibit wood oil and prevent the coatings from yellowing. Its high coverage formula enhances the covering capabilities of the top coating, so less paints and fewer coats are required. It can fill up small holes to ensure a smooth and impeccable finish. High acid-resistance and alkali-resistance prevent spalling and pulverisation of substrates. The product is suitable as a base coat for substrates such as decoration plywoods, calcium silicate boards and cement wall surfaces. Water-based formula for safe application.