Da Vinci Kolinsky Red Sable Series 1311 Flat Brushes. Short Length Kolinsky Red Sable Brushes. All the hair used in DaVinci natural hair watercolour brushes is dressed and prepared in the DaVinci factory by skilled artisans who turn over the prepared hair to experienced brushmakers for hand shaping. In this way, quality standards are assured from raw material to finished brush. The reservoir, or belly, of the brush recharges the tip. Expertly shaped, these brushes have spring, resiliency and colour & water-carrying capacity. Each brush features a durable, seamless ferrule. Approximate full brush length is 19cm. Sizes given below refer to the approximate width of the brush head at the widest point.