Manuscript Ink Cartridges offer a variety of colors of non-waterproof ink. They can be used with any cartridge pen that accepts universal size ink cartridges (1-1/2” long). - Manuscript Ink Refills - Black, Pkg of 24Manuscript Calligraphy, 24 BLACK CARTRIDGES - This set includes 24 non-waterproof, fountain pen ink refills containing Black ink.