How long can you leave ink in a fountain pen before it dries out

Why ink dries inside a pen at all

Fountain pen ink is mostly water, and water evaporates. Brian Goulet of the Goulet Pen Company puts it plainly in his cleaning guide: when a pen sits unused, the ink may start to dry up in the pen because the water in it evaporates over time. He also lists what that feels like: a pen that has sat for a while can seem to be out of ink, write very dry, or skip.

The cap is the main defence. Pelikan's own handling sheet for its fountain pens opens with the instruction to close the pen with its cap every time you are not using it. Everything else in this article is a question of how well the cap, the filling system and the ink itself slow that evaporation down.

What a 69-day test of 28 pens found

The most detailed public measurement comes from a hobbyist, not a manufacturer. The author of the Nibbinibnibb blog filled 28 pens, plus separate converters and cartridges, with Pelikan 4001 Brilliant Turquoise, stored the pens horizontally in an ordinary room, and weighed everything at intervals for 69 days. The author is clear that temperature and humidity were not controlled, so treat the figures as a rough guide rather than lab results.

No pen dried out during the test; every one still wrote at the end. The differences were in how fast ink was lost. In piston-filling pens the ink lasted about 50 percent longer than in cartridge or converter pens, and pens with screw caps held ink roughly twice as long as pens with snap caps. A cartridge or converter left out of a pen was estimated to be finished after about 100 days, while a cartridge left inside a pen was estimated to last about 300 days to well over a year.

Some pens are built specifically for long gaps. Platinum says pens with its Slip & Seal cap mechanism still write smoothly even after two years of not being used with the cap on. At the other end, the pen site Picky Pens notes that while most modern pens are fine for a week or two, some can dry out in a matter of days even when stored well, and that broad and double-broad nibs tend to dry sooner than fine ones.

The ink matters as much as the pen

Ordinary dye-based inks are the forgiving case. Two other families need more attention. KWZ, a Polish maker of iron gall inks, says these inks should be used in fountain pens that are used regularly, and gives a simple test: if a pen dries out after a day or two without use, it is not a good home for iron gall ink. KWZ also notes that nibs of gold, titanium and similar metals are generally resistant to corrosion, while nibs of ordinary steel can corrode, especially if their protective coating is damaged.

Pigmented inks are the other case. In its FAQ, Pelikan says its pigmented Fount India ink should not be kept in a fountain pen for weeks if the pen is not in use. Pelikan's handling sheet goes further for color in general: apart from its 4001 Royal Blue and Edelstein Sapphire, it says pens filled with colored inks need washing more often.

What pen makers and retailers recommend

Advice on cleaning intervals varies a lot, which is itself useful to know. Pelikan's handling sheet says a pen in daily use with its Royal Blue only needs washing about once a year with cool water. For a pen that is used rarely, the same sheet says to empty it every six months and wash it, to clean it before writing if it has not been used for a longer period, and ideally to store it clean with no ink inside.

Goulet's rule of thumb is more cautious: clean a pen about once a month, and whenever you change colors or notice a performance problem. Neither source is wrong. Pelikan is describing its own pens with its own most forgiving ink, while Goulet is advising people who use many brands of pens and inks. If you rotate a lot of different inks, the monthly habit is the safer default.

Signs a pen is drying, and how to bring it back

Goulet lists the symptoms: a pen that has not been used in a while feels as if it is out of ink, writes very dry, or skips while you write. His reading of those signs is that the pen has probably been sitting around too long, not that it needs a refill. Cleaning is the fix; Goulet describes it as rebooting the pen, flushing out dried ink and blockages that built up over time.

For stubborn cases, Pelikan's FAQ says ink crusts on the nib and feed can be removed by washing them in warm water, and that soaking can take up to a week before crusted ink comes away easily. Pelikan's handling sheet also warns never to use dish-washing liquid or alcohol. With iron gall ink there is one extra rule from KWZ: if the ink has dried in the pen, do not let it go back into the bottle; rinse the pen thoroughly instead.

Common mistakes

The most common one is not a cleaning error at all. It is losing track of which pens are inked and when they were filled, which is easy once you rotate more than three or four. A pen at the bottom of a case can sit for six weeks before anyone notices.

Other mistakes come up again and again: leaving iron gall or pigmented ink in a pen you have stopped using, assuming a skipping pen is empty and topping it up instead of flushing it, reaching for soap or alcohol when water and time would do, and judging every pen by the slowest-drying one you own. A screw-cap piston filler and a snap-cap cartridge pen simply do not behave the same.

If remembering fill dates is the weak point, write them down somewhere you will see them. InkRota, a fountain pen ink tracker, records the date you ink each pen and shows how many days it has been, with a signal that follows common practice and can be adjusted. It counts days rather than measuring the pen, so the pen itself is still the final word.

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