Zinsser B-I-N Advanced Synthetic Shellac Primer Sealer provides durable stain blocking protection for interior and spot exterior applications. Compatible with all types of bare or painted surfaces including drywall, wood, masonry, galvanized metal and more. Seals tannin, knots and sap streaks. Seals cigar, cigarette and nicotine odors. Excellent adhesion to slick surfaces like tile, glossy paints and varnishes. Easy to apply by brush, roller or airless sprayer.