Dr. Ph. Martin's Bombay India Inks offer powerful color 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 watercolor techniques or in dip pens, technical drawing pens, and airbrushes. All colors are brilliant and transparent, except black and white, which are opaque and have excellent covering power.