Purdy's Black Bristle Brushes have natural filaments for a smooth finish. They are designed for use with oil-based paints, stains, epoxy, and spar urethanes. Black Bristle brushes hold and deliver more paint than any other natural material, with stiffer bristles for thicker coatings. Naturally flagged tips produce smooth results on a wide range of surfaces. Project types include: bare wood floors, furniture, doors, cabinets, and concrete. 100% Natural Black Bristle.