Dr. Ph. Martin's Black Star India Inks are lightfast, permanent, and waterproof when dry. Hi-Carb is a gloss finish ink with an extremely high carbon content, best when used on acetate where density and line integrity are most important. It produces excellent results when used with technical pens or calligraphy dip pens. Flows through a 4x0 (0.134 mm) pen tip. Also good for works on paper, illustration board, and canvas. While extremely opaque, this ink contains no varnish or shellac.