Wilko Undercoat Paint 750ml improves the adhesion and denseness of your gloss or satin paint top coats, making it the perfect base. It dries in 16 to 24 hours and is suitable for interior and exterior wood. The contents of this can will cover approximately 30 square metres* which after 2 coats, is about the same width as 9 standard doors. (*Approximate coverage depends on the surface of your walls, see the back of can for more details). Wilko Undercoat White 750ml