Tombow Dual Brush Pen Art Marker (N25 LAMP BLACK) Tombow Dual Brush Pens have two tips - a flexible brush tip and a fine-point, hard nylon tip. Both tips are fed from the same ink reservoir ensuring exact color match. Tombow's odorless waterbased inks blend to create any color desired. The colours are water-based and can be used as water-colours and can also be blent. For this purpose, apply the colours to a glossy surface, e.g. an old CD; and blend them with the help of a paint-brush and water. That way you can create beautiful effects and shades!