Description A box of 6 Kaweco Midnight Blue fountain pen ink cartridges. Kaweco Midnight Blue fountain pen ink cartridges are standard short international size, and will fit most fountain pens that accept international cartridges. Please note that they will not fit in pens by Lamy, Sheaffer (except the VFM), Parker, Cross, Pilot, Sailor and many others that use proprietary 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.