Description A set of 6 Cross Blue-Black fountain pen ink cartridges, in a carded blister pack. Cross fountain pen ink cartridges are proprietary, and only fit Cross fountain pens that accept cartridges.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.