Superior Stain Blocking - completely hides dark colors and blocks interior and exterior stains including graffiti, grease spots, tannin, tar, or asphalt and prevents them from bleeding into the topcoat paint. Seals most interior and exterior stains on drywall, builders flat, new wood, cured plaster, masonry and brick. Great adhesion without sanding - sticks to oil-base enamels, clear finishes, Formica, PVC, ceramic tile and even glass, without tedious sanding.