Disposable, technical drawing pens make a range of lines from fine to broad with the four different sizes. Water-based, black pigment ink is water-resistant and fadeproof. Ridges on the barrel provide a sure grip. Drawing pens also include a cap to keep the ink fresh and a clip on the cap to attach to pockets, notebooks and more. Set includes four sizes: 0.1mm, 0.3mm, 0.5mm and 0.8mm.