Brush pen is necessary for both artists and architects for designing and painting. However, traditional brush pen is not convenient for daily use. The Pentel Pocket brush pen is designed to solve this problem. Pentel Pocket brush pen is made of nylon fibers. Its brush head gives almost the same performance as the animal hair. Pentel Pocket brush pen can be used two times longer than regular animal hair made brush pen. Pentel Pocket Brush pen also features its cartridge ink supply system which avoids the solid ink and ink leaking. It can be refilled with Pentel Pocket brush pen cartridges.