From the manufacturer:
Black Star Hicarb (high carbon content) India Ink is best on acetate where density and line integrity are most important. Excellent in technical pens or calligraphy dip pens.
Black Star Matte (matte finish with no light reflection) India Ink is best on paper, illustration board and canvas. Excellent in technical pens or calligraphy dip pens. 1oz. size.