Loved by technical pen users, fine artists and draftspeople alike, Ultradraw ink provides a rich, black India ink with a long open time - it will not clog or smear. It offers optimal results on all drawing surfaces and is also well-suited for airbrushes, crow quills and calligraphy pens. Details:Black india ink0.75 fl. oz. (22 mL)Housed in a .75 oz. filler bottleWaterproof For paper and filmQuick-drying Conforms to ASTM-D 4236