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