These high quality fineline pens contain archival water-based pigment ink and are solvent-free. Durable nibs, made in Japan, deliver a continuous flow of ink. There are four sets which each come in their own wallet. Black, Sepia and Graphite sets of three contain nib sizes: 0.1mm, 0.3mm and 0.5mm. Black set of six contains nibs: 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.5mm and 0.8mm.