Description This 50ml bottle of Sailor Souboku Pigmented Blue-Black fountain pen ink is a high quality choice for the deep rich color and its fast-drying and water resistant properties. This pigmented ink was designed for brush pens, but is safe for use in fountain pens as well. This new deeper darker blue was developed for writers and artists who want a deeper shade of blue than the Sei-Boku. A little extra care is called for, so don't leave it in your pen for weeks on end without cleaning. The pigment particles, if left to dry, can require a little more maintenance to clean out. Sailor Souboku Pigmented (Nano) Blue-Black fountain pen ink dries on the surface of the paper and is perfect for mixed-media or watercolor artists who use thicker sketch or watercolor paper, but this also works well for artists or others who use fountain pens, with a color wash over top.Comes in new 50ml square glass bottle with no internal reservoir. Having trouble deciding between colors? Use our Ink Comparison Tool to quickly and easily view different colors side by side.We offer Free Shipping on all orders over $50 for US customers, and for orders over $250 for our Canadian customers.