Dr. Ph. Martin's Ocean Fountain Pen Ink is an entirely new, pigment based ink for fountain pens. The first of it's kind, Dr. Ph. Martin's Ocean Fountain Pen Ink is lightfast, archival, brilliant, fine artist pigment liquid color designed specifically to flow through fountain pens without clogging. Works great with TWSBI Diamond 500, TWSBI VAC 700, and other high quality fountain pens. Each 1.0 oz (30 ml) glass bottle comes with its own dropper. Available in three colors.