A mixture of sable and synthetic mixed together to perhaps offer the best of both worlds. Sable holds the liquid/pigment and the synthetic offers the spring and durability, whilst maintaining a favourable price. A good all rounder for Watercolours, Oils and Acrylics. 

The Series 769 One Stroke allows you to do what it says! One stroke - loaded with pigment. The longer length of brush head offers a good amount of liquid retention, with a nice sharp edge.