Grumbacher Gainsborough Brushes A Professional line of long handled chung king hog bristle brushes for oils. Brights: Length and width of brush is generally squared. Similar to flats, but shorter hairs make a stiffer brush. Fans: Brush fibers are spread out making it useful for subtle blending and for textural effects. Filberts: Create a softer edge than a flat or bright. Flats: Longer hairs than a bright, this brush has more flex and a large color carrying capability. Rounds: Smaller sizes are typically used for detail work and larger sizes tend to be used for washes and filling in color.