Dr. Ph. Martin's Pen White is the best opaque and whitest ink in the shop. The ink is very suitable for use with calligraphy and airbrush.
The structure of the Pen White is slightly more delicate than the Bleed Proof White. The ink has the same calcareous feel as Bleed Proof and dries matte. I usually use it directly from the jar without diluting it with water. If you think the ink is too thick, you can thin it a little with water. The ink is not waterproof.