Dr. Ph. Martin's Bombay India Ink offers this powerful color in a convenient dropper-stopper glass bottle. This highly pigmented India ink not only remains lightfast and permanent but is also totally waterproof when dry. It adheres to nearly all surfaces and is non-clogging when used in pens. Inks can be diluted with water and used with brushes in traditional watercolor techniques or in dip pens, technical drawing pens, and airbrushes. Each color is brilliant and transparent, except black and white, which are opaque and have excellent covering power. Dr. Ph. Martin's Bombay India Ink is perfect for everyday studio use.