TOMBOW-Dual Brush Pen Set. These dual brush pens have a versatile and flexible nylon fibre brush tip on one end that creates medium or bold strokes by simply changing brush pressure. The fine tip on the other end is for smooth straight lines or writing. The water based ink is blendable, odourless and non-bleeding. Acid free and non- toxic. Perfect for fine art techniques. This package contains six pens. Available in a variety of colour combinations: each sold separately. Conforms to ASTM D4236. Imported.