The Copic Gasenfude bristle brush pen has been popular in Japan for many years, is now available in North America. Ideal for handwriting, calligraphy, comic art, and traditional brush art applications. Water-based, archival, black pigment ink that is not bleed with Copic Markers. Long, flexible bristles are 9mm long and measure 3.1mm diameter at the brush base. Flexible bristles are perfect for detail work. Not refillable, single pen.