This Bombay India Ink from Dr. Ph. Martin comes in a range of 24 colours in 30ml dropper bottles. The ink is heavily pigmented India Ink which is both lightfast and waterproof when dry. It will hold a line without spreading and flows smoothly without tip drying. 30ml dropper-stopper glass bottle. A truly vibrant and easy to work with waterproof ink. Dr. Ph. Martin's Bombay India Inks offer powerful colour in a convenient dropper-stopper glass bottle. These highly pigmented India inks not only remain lightfast and permanent, but are also totally waterproof when dry. They adhere to nearly all surfaces and are non-clogging when used in pens. Inks can be diluted with water and used with brushes in traditional watercolour techniques or in dip pens, technical drawing pens, and airbrushes. All colours are brilliant and transparent, except Black and White, which are opaque and have excellent covering power. They are all acid free, contain fine artist pigments, are non-toxic, Lightfast Archival, and waterproof.