Collection: TWSBI GO

Choose bottled fountain pen ink if you want the widest color selection and a more refillable writing experience. Bottled ink works with compatible fountain pens using a converter, piston filling system, or other bottle-fill mechanism.

Choose ink cartridges if you want a simple, convenient refill option with less setup and easier travel. Cartridges are a good choice for everyday writing, school, work, and anyone who wants a faster refill process.

especially when changing ink colors, every six weeks, or before storing the pen—is essential to prevent ink residue buildup, muddy color mixing, and clogged feeds that can lead to scratchy or inconsistent writing.