SMARTCOAT 200 Asphalt Bleed Blocker is a water-based formulation manufactured with premium acrylic resins that are designed to block bituminous oil exudate or "bleed-through" from staining SMARTCOAT 400 series coatings. Though SMARTCOAT 400 series coatings do not require primer for adhesion to most bituminous surfaces such as built-up roofing (BUR) or modified asphalt, SMARTCOAT 200 also enhances adhesion to these substrates.