There is a particular sound a bottle of ink makes when it rolls the length of a rucksack: a soft glassy clink, half muffled by a jumper, entirely too cheerful for the damage it implies. Most pen spills are not dramatic. They are the result of a cap that worked loose, a converter that came free, or a bottle that spent four hours lying on its side against a book. None of it is difficult to prevent. It just needs five minutes of thought before you zip the case.

What follows is a packing routine built around what actually goes wrong: leaks, burps, cracked nibs, and the quiet disappointment of arriving somewhere with a pen that has run dry and nothing to refill it with.

Decide what is actually coming with you

Travel is not the time to take the whole collection. A workable number for a week away is three pens: one that lives in your pocket or bag and takes the knocks, one for proper writing at a table, and one spare. Anything beyond that is weight you will worry about.

That leaves the harder question of what stays at home. Leave behind the irreplaceable — the pen inherited from a grandparent, the limited run you would struggle to replace, anything with a nib you cannot easily have repaired. Leave behind anything that has already shown a tendency to weep ink into its cap. And leave behind the flex-nibed pen you have not yet learned to control; a train table is not the place to discover that a light touch is needed.

Think about how you will actually write. If you are taking notes standing up, a firm medium nib and a pocket notebook beat a delicate fine nib and a heavy journal. Bring paper you enjoy. The point of travelling with a pen is to use it.

Pens that cope well with movement

Pens with a shut-off valve — vacuum fillers, and the classic eyedropper designs — are the calmest travellers, because the ink sits behind a seal until you open it. Cartridge pens are the next best thing: a sealed cartridge is a sealed cartridge, whether it is in a bag or on a shelf. Piston fillers are fine too, with one rule: travel either full or empty, never half.

Why? A pen that is half full of ink is half full of air. Warm the pen against your body, or take it up to cabin pressure in a plane, and that air expands. Ink has to go somewhere, and the somewhere is usually the feed, the cap and your fingers. A full pen has almost no air to expand. A clean, empty pen has no ink to push out. The halfway point is where the trouble lives.

For the flight itself, keep pens nib-up, since the cap traps whatever comes out. If you write in the air, do it briefly and expect a slightly wet first line.

Ink: bottles, vials and a bag that earns its place

Bottled ink is heavy, breakable and, in hand-luggage terms, a liquid. Treat it as one. A small bottle is unlikely to cause any difficulty, but it is worth checking your airline's current rules and packing ink with your toiletries in whatever clear bag you are using.

The practical answer for most trips is decanting. A 5 ml or 10 ml sample vial holds enough for several refills, weighs almost nothing, and fits in a pocket of a pen case. Fill it nearly to the top but leave a small air gap, because a completely brimming vial can weep past the threads if it warms up. Then tape over the cap with a strip of electrical tape, or wrap the cap in a square of cling film before screwing it down. Label every vial. Two brown liquids look identical at midnight in a hotel room, and you will not enjoy discovering which one was the iron gall.

Bagging matters more than bottling. Two zip-top bags, one inside the other, with the vials standing upright in the inner bag and the air pressed out. Then give the bag a rigid home — a small tin, a plastic food container, or the box your last ink order arrived in — and pad it with a sock. A bottle loose in a bag is a bottle that is going to lie on its side.

The small parts that vanish

Converters, cartridges and cleaning bits are what you forget, and they are the reason a good trip ends with a dry pen and a borrowed biro. Build a small spares pouch and keep it permanently packed. It takes up no more room than a passport.

• Two spare converters, in a zip bag — one fitted to a pen, one loose.
• Four or five sealed cartridges, in the same bag.
• A blunt syringe for refilling cartridges from a vial.
• A few sheets of kitchen towel, folded flat, and a cotton bud or two.
• A small pot of silicone grease if you use an eyedropper pen.
• A spare O-ring if your pen has one at the section.

There is no need to take a full cleaning kit. If a pen needs flushing on the road, a cup of warm water, a syringe and patience will do it. Just do not use hotel soap on a feed, and do not leave a pen soaking in a glass you might knock over.

The packing checklist

1. Choose three pens: one knockabout, one for the table, one spare.
2. Fill the pens you will use fully, or leave them completely empty. Check the converter is pushed home.
3. Decant ink into two or three labelled vials, leaving a small air gap, and tape the caps.
4. Double-bag the vials upright and give them a rigid, padded container.
5. Pack the spares pouch: converters, cartridges, syringe, towel.
6. Put the pens in a case, a roll or sleeves, nibs protected, nothing pressing on them.
7. Keep one notebook and one pen accessible without unpacking the case.
8. Pack a soft cloth for the first wipe after arrival.

By plane, by train, by car

Plane

Cabin pressure drops as you climb, so pens go full or empty, nibs up, and you should expect a burp when you open one after landing. Let the pen sit for a minute, then write the first few words on scrap paper. If ink has crept into the cap, wipe it rather than shaking it.

Train

Pressure is not the problem on a train; vibration and knocking are. Keep pens in a case rather than a coat pocket, and keep the ink vials away from the pen you are using, so you are not unzipping the whole bag every time you want to write. A tray table is a fine desk. A moving one is not a fine place for an uncapped bottle.

Car

A parked car in sun will get hot enough to push ink out of a pen and expand a bottle until it weeps, so do not leave a pen case on the dashboard or the back parcel shelf. If you are crossing a mountain pass, the altitude change is slight but real, and the same rule applies: full or empty, nib up, and check the cap before you write.

The last five minutes before you go

Seal everything, then do one slow check. Cap each pen properly. Push each converter home. Squeeze the air out of the bags and test the zips. Put the spares pouch somewhere you can find it without unpacking. Then leave

Photo: janeb13 / Pixabay