Fountain Pen Converters

A converter is the small piston or squeeze filler that lets a cartridge pen draw ink from a bottle. It is the cheapest upgrade in fountain pens: for the price of a few packs of cartridges you unlock every bottled ink ever made.

Fit is the whole story. Most pens take a standard international converter, but several makers use their own dimensions, and a converter that is a millimetre too wide simply will not seat. Check the pen before ordering; where a maker offers its own converter, that is almost always the right answer.

In use, a converter holds noticeably less ink than a long international cartridge — typically around 0.6 ml against 1.4 ml. That is a fair trade for colour choice, but it does mean carrying a spare fill on a long writing day. To fill, submerge the whole nib past the breather hole, twist the piston down and up, then wipe the nib and section clean before capping.

Maintenance is minimal but not zero. Rinse the converter whenever you change ink, and dry it before storing so that residue does not cake around the piston seal. If the piston becomes stiff, a very small amount of silicone grease on the seal restores it; oil of any kind does not belong near a pen. Converters are consumables in the long run — seals harden after some years — so keeping a spare for a pen you rely on is sensible rather than paranoid.