The Escoda Series 2813 Optima Brushes are made from a custom blend using only the best male and female kolinsky hair. A perfect choice for watercolor, oil and acrylic artists, these brushes retain a perfect point after much use and have exceptional color retention & spring. Escoda brushes continue to be made by hand by the Escoda family as they were since 1933. This is a short handle size #4 filbert brush with bristles measuring a diameter of 3. 87mm and length of 10mm.