International Standard Converters

These converters will fit most pens that use standard 'international' cartridges. Some of the bigger brands, including Parker, Lamy, Platinum, Sheaffer, Sailor and Pilot, use their own proprietary cartridges, and will need their own converters. And some compact fountain pens are too small to fit a standard converter, needing to use short cartridges instead.

The branded converter to go with your brand of pen is the safest option, but as these are generally interchangeable, a cheaper converter may fit and work just as well - Schmidt are a great example, and are likely to be the original manufacturer of many other brands of converters too! Kaweco make smaller converters designed for their Sport pens that can fit in some pens that full-sized converters are too big for.