Dr. PH Martin's iridescent calligraphy colours are shimmering, highly reflective colors are lightfast, waterproof, and archival, with great covering power on black and other dark surfaces, including paper, wood, board, metal, and some plastics.
These colours / inks are dry smooth and even, with no start and stop marks. Use them with pens (both calligraphy and dip pens), airbrushes, and brushes, both for calligraphy or to accent watercolor work.
Use a few drops of isopropyl alcohol to improve flow in calligraphy dip pen tips. For airbrush use, use a 0.2 mm tip (or larger) if ink flow is restricted.