Figure 1-15.—Bristle nomenclature.

Brushes, Continued Brush bristle Paint brush bristles or hair have flattened, split ends called flags. The flags nomenclature enable the bristles to trap pigment and move it around. The end of the and testing bristles, enclosed by the ferrule, is referred to as the butt. Here brush deterioration generally begins with trapped pigment rotting the bristles. When judging bristle elasticity, you should bend the bristles at a 45-degree angle to a horizontal surface and observe where the bristles bend. The bend should occur approximately 1/3 the length from the ferrule. The bend of the bristle is called a heel. A brush that is too stiff to bend or bends too near the tip is an inferior brush. Figure 1-15 shows bristle nomenclature. Figure 1-15.—Bristle nomenclature. Continued on next page 1-26