Introduction This fresh take on Kaweco ink contains its original formula, offering the same high-quality writing experience as is predecessor, but with a newly designed ink bottle and eco-friendly packaging. About the Ink The ink is water-based and designed for use with fountain pens. It is highly saturated with coloured pigment, creating vibrant or bold colours on the page when writing. Each ink bottle contains 50ml of ink, ideal for keeping on your writing desk when your pen needs to be refilled. They are colour themed and along with their ink converters (sold separately), so if you're a fan of Kaweco inks and like to experiment with different colours, you know exactly which converter goes with which ink. What is an ink converter? Ink converters are essentially an empty ink cartridge that you can fill with bottled ink. This is a great way to support our environment, as it takes away the need to dispose of empty ink cartridges, which are made from plastic. You can find Kaweco ink converters ink our Inks & Refills Department.