Sheaffer Classic Ink Cartridge (Pack of 5) Blue-Back. Sheaffer’s high-quality cartridges are perfect for use with Sheaffer fountain pens and are available in a range of outstanding colours. Sheaffer inks are available in a wide selection of unique and vibrant colours. The distinctive ink colours will make your writing stand out from the crowd, showcasing your style and personality. This cartridge fits most current Sheaffer fountain pens including calligraphy pens. It is not suitable for the Sheaffer VFM.