kilz Original White Matte Oil-Based Alkyd Primer, Sealer and Stain Blocker 5 gal.kilz Original has been a trusted brand for over 40 years! This interior and exterior primer is specially formulated to be a sound undercoat for paint and will help enhance the topcoats performance. It has excellent adhesion to both interior and exterior surfaces including masonry, metal and excellent penetration for bare wood. kilz Original Interior Exterior is a fast drying sealer that blocks most severe stains including tannin bleed, graffiti,