How to Fill a Fountain Pen

So you want to fill your fountain pen? The first thing you have to consider is what to fill it with. Fountain pen ink would be our recommendation. It’s better than most of the alternatives. Actually, it’s probably better than all the alternatives. You could try filling it with paint, but it’s not going to end well. Cheese wouldn’t work, even melted like a fondue.

And don’t even think about calligraphy inks - they can be pigmented, and can contain things like shellac to add extra shine, and they’ll just clog up your fountain pen. Anything sold as fountain pen ink should be ok, though there’s a little more risk with some of the more fancy inks with shimmer and sheen - a nice plain and simple ink is the safest option. But those fancy ones can be fun, and they should be just fine as long as you don’t leave them to dry out in your pen.

The first question is what filling system your pen has. Some have their own ink reservoir rather than using a converter, and they can vary quite a bit, so you may need to look for more specific instructions if you have one of these pens. But the vast majority of fountain pens use cartridges or converters, and most of the others use a piston mechanism which works pretty much the same as most converters.

Cartridges

These are the simplest, and most common way of filling a fountain pen. The main thing to watch out for is that you get the right cartridges for your pen. A lot of different pens use standard ‘international’ cartridges - these come in two sizes, where the larger ones don’t work in some pens. Full-sized pens can usually take the larger ones, but they usually also have another little trick. With many pens, you can fit one cartridge in the pen to use, and another one turned around the other way, in the barrel above the cartridge that’s in use, so you always have a spare. Very handy.

Some pens, especially the bigger brands, have their own designs for cartridges, so you have to buy their own. The cynical interpretation of this is that they make more money that way. There are more historical reasons, though, which may excuse it somewhat - everyone made their own at first, and the bigger brands just continued with their own designs. Smaller brands, and those coming later to the cartridge game, usually just went with the standard, which was the design Montblanc had started. The likes of Parker, Sheaffer and Lamy, for example, had already been making their own cartridges for a while when the standard became standard, so they just carried on.

Anyway, let’s avoid getting caught up in a discussion of capitalism and standards and profits, because that doesn’t get ink into our pen, which is why we were here in the first place.

Cartridges are pretty simple, which is a lot of their appeal. Take the cartridge, stick it into your pen, pushing it onto the back of the nib unit, and it should click into place. You’re done. The only bit that might be questionable is which way round it goes. The usual rule here is that the more interesting-shaped end goes in behind the nib. The way cartridges usually work is that they’re sealed by a little ball in the tip, and the back of the nib unit pokes into the end of the cartridge, pushing that ball up into it. Once you know that, you can probably see which end has the little ball.

A little side-note - that ball ends up inside the cartridge with the ink, and it can serve a purpose in there. Because cartridges are narrow, the ink can actually end up stuck inside, when surface tension in the ink wins out over gravity. Kind of like how a bit of drink could get stuck in a thin straw. The ball falls, and breaks the surface tension, letting the ink drop down to where it was supposed to be.

Converters

A converter fits in place of a cartridge, so you can use bottled ink instead. You lose a bit of convenience, but you can a whole world of choices of inks to use. If you’re still a bit riled up about those dastardly capitalist pen companies and their proprietary cartridges, just get a converter. Then you can use all the bottled fountain pen inks the world has to offer.

If your pen is new, and came with a converter, it might have arrived already fitted in the pen. If you open your pen barrel and there’s a filling mechanism on the inside, it’s probably a converter, which you’d pull out to use cartridges instead, if you wanted to. But then you’d have to scroll all the way back up to the cartridge section. You’re down here now, might as well use bottled ink.

Essentially, it’s a refillable cartridge. Which might make you think you’d fill it up from a bottle, then put it in your pen. And you can do it that way, if you like, but it’s not usually the best way.

Before we continue, check that your converter is of the type we’re talking about here - a piston converter. Most are, but there are a few exceptions we’ll mention further down. If it is, it’ll have a part that turns, and when you turn the turny bit, a piston will wind up and down inside the converter, pushing ink down and pulling it up. If that doesn’t sound like what you have, skip forward a bit to the ‘Odd Converters’.

OK, we may have given away the method in the last paragraph tbh. You wind down the piston until it’s at the bottom. You dip the nib into ink. Then you wind the piston back up. The bit that isn’t necessarily obvious is that you really need to dip the whole of the nib into the ink, right up to the grip section. If any air can get in, it will. If you’ve ever used a drinking straw, you know it’s easier to suck air than water, and ink is mostly water. So if you leave a bit of the nib out of the ink, you’ll mostly suck in air instead. Not what you want. Air doesn’t write very well. Or maybe it does, it’s just very hard to read. It’s a question for philosophers, not us.

Once you have ink in your pen, you probably also have ink on the grip section, which is likely to make a mess of your fingers. You can wipe it off with a bit of tissue, or just accept that you’re a weird fountain pen person now, and you’re going to be going around with ink-stained fingers. It’s just how we live. Sorry nobody warned you.

Some people also wrap a bit of extra tissue around the nib for a second, just to draw out some excess ink. This can help avoid drips, but watch out - the ink soaks straight through a lot of tissue quite quickly, and you’re back to those ink-stained fingers. One of us, one of us, one of us. The alternative method for this is to wind the piston back down a short way to expel a couple of drops back into the bottle, then wind it back up - it’s not necessary, especially if you’re about to use your pen, but might help avoid a drip inside the cap if you’re not.

Odd Converters

The vast majority of converters work as described above, but there are a few oddities.

• Push-pull pistons - these use a piston, but instead of a winding mechanism to move it up and down, you just push and pull it directly. They’re a bit less elegant, but they’re quicker to use. Some TWSBI converters are like that, and some Parker converters. Sometimes these have a spring to push them back up.
• Button converters - the only example we can think of is Pilot - some of their high-end pens use a button converter, where you ‘pump’ a button on the end to fill. They can hold more ink than the same sized piston converter.
• Sac converters - again, rarely seen, but Kaweco used to make one to fit the Liliput. The entire body of the converter is a rubber sac, which you squish down between your fingers - it springs back into shape when you release it, filling with ink. Very simple, and can work in pens too small for anything else.

Piston Fillers

These work the same way as a piston converter, but there’s no converter - the barrel of the pen holds the ink and piston mechanism directly. The disadvantage is that you can’t use cartridges, and the piston can’t be replaced easily if it breaks. But they hold a lot more ink, and they’re very reliable. There are piston fillers from maybe 60 or 70 years ago where the only maintenance they need is to replace a little cork seal. Modern piston-filled pens use silicone or similar rubber seals, so they should last even longer.

Vacuum Fillers

A great option if you want even more ink capacity than a piston-filled pen. They look quite similar, but the part that looks like a piston sits right at the bottom when in use, with the ink above it. The way it works is that the ‘piston’ part makes a tight seal most of the way through the barrel, but the centre part is wider at the top and bottom, breaking the seal. The piston bit is also sort of ‘cup-shaped’, pointing downwards, so it makes a strong seal on the way down, but not so much on the way up - it can flex a bit on the way up to let air or ink pass by.

Unscrewing the top will release the piston to move. Pull it up to the top, holding it somewhere a spill won’t matter, as ink can drip out at this point. Then dip the nib into the ink, and push the piston all the way to the bottom in one movement. The seal it creates in the barrel creates a vacuum behind it. When it reaches the wide part at the bottom, suddenly air tries to flood in to fill that vacuum. Abhorring it, even. Nature does that, apparently. But it can’t get in because the only way in is blocked with the ink in your ink bottle - so the ink is sucked in instead.

A vacuum filler can fill most of the barrel with ink in this way, in a few seconds - they’re very quick, and have a huge ink capacity. They’re also very reliable, much like a piston filler.

The Gotcha of Vac-Fillers

A lot of vacuum-filled pens have an extra little trick, which catches people out. When the mechanism is closed up, screwed down at the top, the piston often blocks off the ink from reaching the nib, which means the pen will write a little bit, then dry up, even though it’s full of ink. Unscrew the piston, and wiggle it a little if needed, and ink can get to the feed and nib. Screw it back down to seal it up again when you’re done writing.

It’s a little bit of extra hassle, and may be one of the reasons these pens aren’t more popular than they are, but if you don’t mind the little extra work, it’s done for good reasons. Changes in air pressure and temperature can cause some pens to leak, and with the large amount of ink and air in the barrel, vacuum fillers are especially prone to this. By sealing off the ink flow when not in use, the problem is gone. If you’ve brought the pen in from a colder place to a warmer one, you can open the valve with it tip-up to let the pressure equalise before you start using it. You can let ink through to the feed only as needed, so the risk is reduced as the pen warms up.

For some, it’s an extra complication they just don’t want. For others, it lets them be in control of the pen, and makes it safer to use in conditions other pens could leak in.

Vintage Pens

We can’t really cover vintage pens here, there are just too many different filling systems that have been used over the years. Many vintage pens will need some restoration work, and trying to force the mechanism could do more harm - try moving parts gently. It’s best to ask on a forum, like one of the fountain pen subreddits or Fountain Pen Network to find out what sort of filling system you’re looking at, and if it’s likely to need restoring before use.