da Vinci Hog Bristle Series 7123 Maestro 2 Artist Paint Brush, Bright with European Sizing, Size 4 Highest quality chungking bristle is double boiled for extra spring and endurance. This allows for maximum stroke control that is not possible with overly stiff bristle. They are interlock constructed so they keep their form after long and vigorous use While being hand shaped, stiffer bristles are removed to ensure better flags at the tips Better flags distribute color more evenly than bristle that is simply cut flat at the end.