Helix Pigment Liners,Pack of 4 (0.1 mm, 0.3mm, 0.5mm and, 0.8mm) (37235) 4pk black pigment liners include: 0.1mm, 0.3mm, 0.5mm, 0.8mm Disposable, technical drawing pens with water-based, water-resistant and fade-proof black ink. Metal reinforced collar nib is suitable for ruler and template work. Textured barrel for comfort and a sure grip.