It maintains a perfect point, has moderate length, and handle lengths from moderate to long. Small rounds are used primarily for detail work and signatures. Medium to large rounds are used more for utility paint application. Ferrules are usually nickel. Fans are used for creating repetitious shapes like fur or grasses.
Blenders have long, soft hairs and are ideal for blending one area of color seamlessly into another.
These come in many hair qualities, but are one place where one might expect to find exotic hairs used. Ferrules are usually nickel. Care of fine brushes is essential to their long life. One accepted method for cleaning oil brushes is to first remove the excess paint with an old rag. Then clean a second time in a fresh solution to remove all traces of paint.