All possess their own strengths and offer unique qualities. Most quality watercolor brushes are constructed by taking select brush fibers and securely binding them onto an attractive wooden handle with a stain-proof metal ferrule. A well-constructed brush should feel comfortable in the hand and have a certain degree of balance. Sable brush hairs come from a variety of animals in the weasel and mink family. Among these bristles, Kolinsky hair is the finest and most expensive due to its thick and highly resilient texture.
All sable brushes have excellent water-retention qualities and spring well when wet.
The best squirrel hair for watercolor brushes comes from the tails of Russian squirrels, while lesser-quality fibers are obtained from Canadian squirrels. This type of hair is quite soft, retains water well, and holds a point when wet but does not spring as well as sable. Best uses for this type of hair are typically flat and oval wash brushes. The best application for this type of hair is a mop brush used to lay down large area washes. Ox hair is often blended with other fibers to lend water retention and flexibility.