Write with confidence on the pages of your Notebooks and Planners with a Tombow refill. These refills are specially formulated with Tombow's permanent, waterproof ink which permits writing at any angle. The Tungsten carbide rolling ball gives a beautiful line of unequaled smoothness that won't skip, smear or fade. The ink is acid-free and smudge-proof so you know your writing will be legible for years to come.