High quality red sable is used throughout the line. The rounds are 100% pure Kolinsky sable – the undisputed king of watercolor hair. Sable has a natural ability to hold lots and lots of color and delivers it with great control to the painting surface. The natural spring of sable allows these brushes allows these brushes to snap back to a precise point with only a flick of the wrist. Treated with care, these brushes should be in service for some time.