Purdy's White Bristle Brushes provide an ultra smooth finish and are designed for use with oil-based paints, stains, polyurethanes, wood conditioners, lacquer thinners, and clears. White Bristle brushes are the most versatile natural bristle brush for oil-based coatings & projects. Project types include: decks, siding, floors, furniture, antiques, or any other application that calls for an extremely smooth finish, these brushes will give outstanding results. 100\% Natural White Bristle.