I refill fountain pens three ways: with a cartridge, with a converter, or with the pen’s built-in filling system. If you are new, the safest rule is simple: unscrew the barrel, identify what is attached to the back of the grip section, and refill that system instead of guessing. In practice, most beginner pens are cartridge/converter models, and the cleanest refill is either snapping in a fresh cartridge or dipping the nib into bottled ink and drawing ink up with the converter.
If you’re trying to make a smart choice instead of buying twice, that sounds basic, but the details matter. Over the last decade I have tested more than 200 pens, and refill mistakes cause more “my pen is broken” complaints than bad nibs do. The usual problem is not the pen. It is using the wrong cartridge standard, not submerging the nib deeply enough, or trying to force ink into a pen that has a built-in piston or vacuum filler. Goulet’s filling mechanism guide is still one of the clearest breakdowns of the main systems, and their compatibility chart is a useful reminder that many brands do not share the same cartridge or converter format.
The Short Answer
Here is the beginner-safe method I recommend. First, unscrew the barrel and check what your pen uses. If you see a disposable plastic tube, that is a cartridge. If you see a removable refillable reservoir with a twist knob or squeeze sac, that is a converter. If nothing detaches and the whole pen body has a knob or plunger, you likely have a piston or vacuum filler. Those distinctions matter because the refill steps are different.
For a cartridge pen, remove the empty cartridge and press in a compatible new one until the seal is pierced, then reassemble the pen and wait a minute for the feed to saturate. For a converter, twist the piston down, submerge the nib and part of the grip in bottled fountain pen ink, then twist back up to draw ink in. For piston and vacuum pens, the same principle applies, but the filling mechanism is built into the pen body. Goulet and JetPens both note that modern fountain pens commonly use cartridge/converter or built-in fillers, and that larger built-in systems usually hold more ink but are less convenient to clean. See Goulet’s overview and JetPens’ notes on piston fillers such as the TWSBI Classic.
- Unscrew the barrel and identify the filling system.
- Use only fountain pen ink, never India ink or calligraphy dip ink.
- For bottled fills, submerge the nib past the breather hole before drawing ink.
- Wipe the nib and section with a paper towel after filling.
- Test on scrap paper for 10 to 20 seconds before assuming something is wrong.
Why This Matters More Than Most Beginners Think
Refilling is not just a maintenance chore. It affects how reliably the pen starts, how messy it feels to own, and whether you end up blaming the nib for a filling problem. In my testing, a pen that is filled cleanly and all the way will often feel smoother and more consistent on the first page than the same pen with a half-primed feed or trapped air in the converter.
- Wrong refill method creates fake performance problems. A dry, skipping first line often comes from incomplete filling or poor priming, not a defective nib.
- Compatibility is not universal. Standard international cartridges exist, but Pilot, Platinum, Sailor, and LAMY all use proprietary systems in many models, so random cartridges rarely fit well. Goulet’s compatibility guide is worth checking before you buy spares.
- Bottled ink opens up better value. A converter usually costs a little up front, but bottled ink gives you far more color choice and lower long-run cost than disposable cartridges.
- Cleaning becomes easier if you buy the right small tools. A blunt-tip ink syringe and a bulb syringe solve a lot of refill and cleanup friction for very little money.
The last point is not theoretical. A bulb syringe dramatically speeds up flushing a grip section, which matches Goulet’s cleaning guidance for cartridge/converter pens: run water through the section and use a bulb syringe when you want faster, more complete flushing. Their step-by-step cleaning article is here: How to Clean a Fountain Pen: Cartridge/Converter. If you plan to refill empty cartridges with bottled ink, an ink syringe is the neatest method by far.
The reason this topic matters is that nib size quietly changes almost everything a beginner notices first: smoothness, control, ink flow, dry time, and how forgiving the pen feels on ordinary paper. People often assume nib width is just a style preference, but in practice it changes the whole learning curve.
I have also found that beginners blame the pen when the real mismatch is width versus paper or width versus handwriting size. A nib that feels expressive to one person can feel messy, slow-drying, or oddly broad to someone who writes smaller or uses cheap office paper every day.
That is why I treat nib size as a practical fit question, not a collector trivia question. The right width makes the pen easier to trust, which is a big deal when you are still deciding whether fountain pens are enjoyable enough to keep using.
What I Look for First
When I pick up a fountain pen I have not used before, I check four things before I even reach for ink. This saves time and prevents most beginner mistakes.
- How the pen actually fills. Cartridge/converter, piston, and vacuum pens need different handling. Goulet’s filling mechanism guide covers the main types clearly.
- Whether the cartridge or converter is proprietary. This is the first trap for new users. Pilot especially is its own ecosystem; Goulet’s Pilot compatibility note says Pilot pens use Pilot cartridges and Pilot converters, not standard international ones: Pilot compatibility note.
- Nib depth during filling. You want the nib fully submerged, usually up to part of the section, so the feed can draw ink without inhaling air. Half-dipped fills are one of the fastest ways to get a frustratingly low fill.
- How easy the pen is to clean later. Cartridge/converter pens are usually the easiest beginner choice because the filling unit is removable and replacement parts are cheap.
My bias is practical here: for most people, a cartridge/converter pen is the sweet spot. You get cartridge convenience on travel days and bottled-ink flexibility at your desk. If your pen did not come with a converter, buying the correct one is usually smarter than buying a second cheap pen. A simple standard international fountain pen converter is useful only if your pen actually accepts that standard; otherwise search by brand and model.
My first filter is handwriting size. If you naturally write small, cramped notes, a broad wet nib usually makes life harder before it makes anything more beautiful. If you write bigger, slower, or more expressively, a fine nib can feel a little too restrained unless the paper is poor enough to demand it.
I also pay close attention to paper quality because nib size and paper behave as a pair. A medium nib on Rhodia or Tomoe River can feel controlled and generous, while the same nib on cheap copier paper may feather enough to make the line look clumsy. That is not the nib lying to you. It is the surface exposing the tradeoff.
The third thing I look at is how much patience the writer has for dry time and ink management. People who want neat, fast notes with minimal fuss usually do better starting narrower. People who want more shading, softer feel, and a little more personality on the page can usually tolerate going wider.
How to Choose Without Overbuying
Beginners tend to overcomplicate refill gear. You do not need a lab bench. You need the right refill method, one dependable ink, and maybe one cleaning tool.
- If you want zero mess, start with cartridges. They are fast, travel-friendly, and good for confirming the pen works before you troubleshoot anything else.
- If you want more ink choices, add the correct converter. This is the best upgrade for most new owners because it keeps the pen simple while unlocking bottled ink.
- If you write a lot, consider a piston filler later. Built-in pistons usually hold more ink, but I do not think they are the best first answer for someone still learning compatibility and cleaning.
- Buy one conservative bottle of fountain pen ink before you buy five trendy colors. A basic, well-behaved bottled fountain pen ink tells you more about the pen than a highly saturated shimmer ink ever will.
My own beginner checklist is brutally short. Use the cartridge that came with the pen first. If the pen writes well, add the matching converter. If you want to reuse an empty cartridge instead of buying a converter, refill it with a syringe and bottled fountain pen ink. Goulet has a dedicated guide for that method here: How to Refill a Fountain Pen Ink Cartridge. In practice, I use syringes more than eyedroppers because they are cleaner, more precise, and easier around narrow cartridge openings.
Quick refill breakdown by pen type
| Pen type | Best refill method | Best for | Main downside |
|---|---|---|---|
| Cartridge | Insert a new compatible cartridge | Fastest, least messy setup | Limited ink choice and higher ongoing cost |
| Converter | Dip nib in bottle and draw ink through converter | Beginners who want bottled ink without complexity | Lower capacity than piston fillers |
| Piston filler | Twist built-in piston while nib is submerged | Frequent writers who want bigger capacity | More involved cleaning |
| Vacuum filler | Use plunger to pull ink into the barrel | Large capacity and travel-friendly shutoff designs | Most confusing for first-time users |
If you are standing at your desk wondering what to buy today, my opinionated answer is this: do not overbuy accessories until you know your pen’s filling standard. In my testing, the cheapest mistake is a spare converter. The most common waste is buying the wrong spare converter.
Common Mistakes and Misconceptions
The biggest misconception is that every fountain pen refills the same way. They do not. Some pens are meant for cartridges only, some accept converters, and some have a built-in mechanism that makes cartridges irrelevant. The second misconception is that more expensive automatically means easier. It often does not. A basic cartridge/converter pen is usually easier to refill cleanly than a vacuum filler, even if the vacuum filler is technically more advanced.
The other mistake I see constantly is under-submerging the nib when filling from a bottle. You need the nib and feed properly in the ink so the pen draws liquid instead of air. I also would not chase a completely full converter on the first try if the pen writes well already. Some converters, including smaller designs, simply do not fill dramatically on one stroke, and that is normal. Finally, clean with water before switching inks instead of topping one random color onto another. Goulet’s cleaning guidance and general care article both emphasize flushing with clean water until it runs clear: How to Clean a Fountain Pen. That one habit prevents a surprising amount of sludge, hard starts, and false nib diagnosis.
The biggest misconception is that broader always means smoother and therefore better. Broader nibs can feel smoother, but they also dump more ink, show more paper weakness, and create longer dry times. That tradeoff is worth it for some writers and deeply annoying for others.
Another mistake is trusting brand labels as if every fine or medium were standardized. They are not. A Japanese fine can feel closer to a Western extra-fine, and two medium nibs from different makers can still land in very different places on the page. That is why example use cases matter more than marketing words.
I also think people underestimate how much ink choice changes the perception of nib size. A wet ink in a medium nib can behave more broadly than expected, while a drier ink can calm down a pen that initially feels too generous.
Bottom Line
If you want the shortest practical answer to how to refill a fountain pen, it is this: identify the filling system first, then refill only the system your pen was designed to use. Cartridge pens get a compatible cartridge. Converter pens get bottled fountain pen ink drawn up through the nib. Piston and vacuum pens refill through their built-in mechanism with the nib submerged. Everything else is cleanup and compatibility management.
For most beginners, I recommend starting simple: use the included cartridge, confirm the pen writes correctly, then move to the right converter and one dependable bottle of fountain pen ink. That path is cheaper than trial-and-error buying, and it tells you quickly whether the pen itself is any good. The best refill method is the one that keeps you writing instead of troubleshooting.
If you want the safest beginner answer, I would still lean fine or medium before anything more extreme. Those widths usually give you enough character to enjoy the pen without forcing you to manage every downside at once.
From there, the smartest upgrade path is not buying more expensive immediately. It is noticing whether you want a cleaner line, more expressive ink behavior, less feedback, or more control on cheap paper. Once you know which direction you want to move, choosing the next nib size becomes dramatically easier.