... bristle is the best choice for oil-based paints, varnishes, shellac, alkyd enamels, oil stains, and oil-based polyurethanes. The highest quality comes ... a synthetic brush for paint rough surfaces—even when using oil-based paints.The most important part of a paint brush ... of the brush, but it also sacrifices capacity, coverage, and control. It won’t release paint like tapered filament. If the ...