Watercolor brushes typically have long, absorbent hairs, and the best are of natural fiber. By tradition, a watercolor brush has a short handle, since the artist executes fine detail and works close to the paper or medium.
High-end watercolor brushes, such as Kolinsky sable pointed rounds, are prized for their ability to keep a fine point, useful for detail work. Desired qualities include resiliency and snap.
The cost and scarcity of high-quality natural fibers has fostered the development of good synthetic alternatives. Synthetic watercolor brushes can be used with other media.