This 30ml bottle of Dr. Ph. Martin's Pen-White ink is perfect for fine writing, and was made to be used in technical pens and airbrush. This liquid product delivers the same brightness and permanency of traditional watercolours in tubes, but is much more versatile and easy to use. It will also adhere to a variety of surfaces that include film and acetate-type material. The colour is incredibly opaque and can cover dye and marker colour. Comes in a 30ml glass bottle with dropper. Made in the USA.