Description Sailor Sei-boku Pigmented Blue-Black fountain pen ink is a deep, rich shade of blue-black that is pigmented and water-resistant. The cardboard box contains 12 Sailor Sei-boku Pigmented Blue-Black fountain pen ink cartridges, which are proprietary, and only fit Sailor fountain pens that accept cartridges. This pigmented ink was designed for brush pens, but is safe for use in fountain pens as well. 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 Sei-boku Pigmented 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. Sailor fountain pen ink is made in Japan, and is very well behaved, has good flow, and is easy to rinse out of your fountain pen. 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 $59 for US customers, and for orders over $250 for our Canadian customers.