Stilform names its pens after series, not after colors or materials: AEON is the pencil with a magnetically interchangeable tip (and, alongside it, a twist-action ballpoint pen), PEN is the ballpoint pen with a magnetic cap, FLOW is the rollerball pen, ARC is the gel pen, and INK is the fountain pen. Each series is available in aluminum; most are also available in titanium, and some in brass, magnesium, or 24-karat gold. This guide explains what distinguishes the five series, which refill fits which pen, and which Stilform pen is best suited for which type of writing.
Five Series, One Principle
All Stilform pens are based on the same concept: a sleek metal body with no visible mechanism, no clip, no click button, and no unnecessary engraving. What sets them apart lies inside: the writing system. A pencil with a metal tip writes differently than a gel pen with a 0.3-millimeter refill, and a fountain pen with a gold nib is a different tool than a ballpoint pen for your back pocket. The confusion arises because the pens look almost identical from the outside and come in the same eight colors, ranging from Comet Grey to Velvet Berry. The table clears things up.
| Series | Writing System | Latch or Mechanism | Length | Weight (aluminum) | Rock or Paper |
|---|---|---|---|---|---|
| AEON pencil | Pencil | magnetically interchangeable tip | 134.6 mm (Nano 94.9 mm) | 27 g (Nano 23 g) | Eternal pencil lead (such as 2H) or HB / 2B graphite |
| AEON ballpoint pen | Ballpoint pen | concealed rotating mechanism in the tip | Not specified | Not specified | G2 standard, e.g., Schmidt P900 |
| PEN | Ballpoint pen | self-aligning magnetic cap | 137 mm | 60 g | G2 standard, e.g., Schmidt P900 |
| FLOW | Ballpoint pen | Magnetic cap | 137 mm | 35 g | Schmidt P8127 (also P8126, P8120) |
| ARC | Gel pen | Magnetic cap, anti-roll body | 142.5 mm | 35 g | Pilot Juice Up LP3RF, 0.3 / 0.4 / 0.5 mm |
| INK | Fountain pen | Magnetic cap, converter included | 152 mm | 70 g | Pen Type 076 by Peter Bock, EF / F / M / B |
Dimensions and weights are from stilform.com and apply to the aluminum version. Titanium and brass weigh more, while magnesium weighs less; more on that below.
AEON Pencil: A tip that doesn’t get shorter
The AEON pencil is the product that made Stilform famous. The tip is held in place magnetically inside the barrel: just pull it out, snap on a new one, and you’re done. There are two types of tips. The Eternal tip is made of a non-toxic metal alloy that leaves a mark on paper similar to a hard 2H pencil and wears down so slowly that Stilform describes it as having a practically unlimited lifespan. The graphite tip is made of real graphite in HB or 2B—softer and darker—and wears down gradually; it can be sharpened with fine sandpaper. If you order the Eternal version, both tips are included. If you choose only the graphite version, you can purchase the Eternal tip separately later.
There are three aluminum versions within the series, and this is where the second common source of confusion lies. The AEON features a wood veneer accent on the barrel, is 134.6 mm long, and weighs 27 g. The AEON Pure is the same pen without the wood—all metal—and has the same dimensions. The AEON Nano is the shorter version, measuring 94.9 mm and weighing 23 g, designed to fit in a jacket pocket or a notebook with a pen loop. All three have flattened sides to prevent them from rolling off the table, and all three use the same nibs.
In addition, there are material variations featuring the same mechanism: titanium in matte, DLC-coated, or polished finishes; brushed brass, which develops a patina over time; magnesium, the lightest version; and the AEON 24k Gold with a gold-plated body and wood. For a detailed look at how the Eternal pencil performs in everyday use, see the article on the AEON pencil.
AEON Bleistift Aluminium
Bleistift aus Aluminium mit magnetisch wechselbarer Spitze. Die Eternal-Spitze schreibt jahrelang ohne Nachspitzen, die Graphit-Spitze liefert klassisches HB-Gefühl. 134,6 mm…
AEON Nano Bleistift Aluminium
Der kurze AEON: 94,9 mm statt 134,6 mm, damit er in Jackentasche und Notizbuch-Schlaufe passt. 23 g, Aluminium, magnetischer Spitzenwechsel…
AEON Ballpoint Pens or PEN: Two ballpoint pens, two mechanisms
That’s the question we get asked most often. Stilform makes two ballpoint pens, and both use the same G2-standard refill. The difference lies in the mechanism. The AEON ballpoint pen has a concealed twist mechanism: You twist the front part of the barrel, and the refill extends; there’s no visible button on the outside. The tip features a guilloché pattern—a finely engraved design that serves as a grip zone. It’s available in aluminum and titanium.
Instead, the PEN ballpoint pen has a cap that closes magnetically and aligns itself as it does so. No threads, no click. When writing, you attach the cap to the back, where it also holds magnetically and shifts the center of gravity backward. Weighing 60 g in aluminum, it’s significantly heavier than the AEON pencil; the titanium version weighs 75 g, and the brass one even more. If you want a pen that you can open with one hand and slip into your shirt pocket, go for the AEON ballpoint pen. If you like the weight and the gesture of unscrewing the cap, go for the PEN.
AEON Kugelschreiber Aluminium
Kugelschreiber aus Aluminium mit verdeckter Drehmechanik: kein sichtbarer Knopf, keine Klemme, nur eine durchgehende Silhouette. Die guillochierte Struktur an der…
PEN Kugelschreiber Aluminium
Kugelschreiber mit magnetischer Kappe statt Klickmechanik: sie richtet sich beim Schliessen selbst aus und sitzt ohne Spiel. 137 mm, 60…
FLOW Rollerball Pen: A Cross Between a Ballpoint Pen and a Fountain Pen
A rollerball pen writes with liquid ink instead of ballpoint ink. The result is a richer, darker line that requires less pressure to write, without the maintenance of a fountain pen. The FLOW uses the Schmidt P8127 from the Black Forest, a reservoir-style refill that writes from the very first stroke—even after sitting in a drawer for days. The Schmidt P8126 and P8120 are also compatible, so you’re not limited to a single brand. The barrel is 137 mm long and weighs 35 g in aluminum; the cap closes magnetically. As with the PEN, it’s available in titanium and brass.
One thing you need to know: Always make sure the cap is completely closed after writing. An exposed rollerball refill will dry out at the tip, and that’s the most common reason for skipping in rollerball pens. If you’re the type of person who constantly leaves your pen open on the table, you’re better off with a ballpoint pen.
FLOW Tintenroller Aluminium
Tintenroller mit Schmidt P8127 Mine: fliesst williger als ein Kugelschreiber, ohne die Wartung eines Füllers. 137 mm, 35 g, Aluminium…
ARC Gel Pen: For Fine Lines
The ARC is the pen for anyone who finds a ballpoint pen’s line too wide. It uses the Japanese Pilot Juice Up LP3RF, a gel refill available in 0.3, 0.4, or 0.5 mm, which is permanent and smudge-proof. A 0.3 mm line width ensures that small handwriting, bullet journals, and architectural sketches remain legible. At 142.5 mm, the ARC is the longest of the cap pens; made of aluminum, it weighs 35 g. The barrel features an anti-roll design, so it stays in place even on a slanted tabletop, and the magnetic cap aligns itself automatically when closed. For on-the-go use, there’s the Stilform Clip, which fits both the ARC and the AEON pencil. If you prefer titanium, the ARC Titan is available in the lineup.
ARC Gelschreiber Aluminium
Gelschreiber mit japanischer Pilot Juice Up Mine in 0,3, 0,4 oder 0,5 mm. Das Anti-Roll-Design hält ihn auf dem Tisch,…
INK Fountain Pens: Configure Instead of Buy
The INK is the most complex pen in the lineup because it isn’t finished when you order it. Three body colors in aluminum (or two in titanium), four nib materials, and four nib widths result in 48 combinations for the aluminum version alone. The nibs are made by Peter Bock in Germany (Type 076) and can be replaced at any time: Polished steel as a gentle introduction, black steel with the same writing characteristics and a matte finish, titanium with a bit of flex and direct paper contact, and 14-karat gold as the softest and smoothest nib. As for nib widths: Extra Fine for tight handwriting on thin paper, and Broad for signatures.
A converter is included. This allows you to draw ink directly from a glass container—such as the TILT inkwell—so you’re not limited to cartridge inks. International standard cartridges also fit. Measuring 152 mm and weighing 70 g, the INK—made of aluminum—is the longest and heaviest pen in the Stilform line; like the PEN, FLOW, and ARC, its magnetic cap closes without a click. Replacement nibs are available individually as the INK Fountain Pen Nib, along with the converter and a separate clip.
INK Füllfederhalter Aluminium
Füllfederhalter, den du selbst zusammenstellst: drei Farben, vier Federmaterialien von Edelstahl bis 14 Karat Gold, vier Federbreiten. 152 mm, 70…
Aluminum, titanium, brass, magnesium, gold: How the material makes a difference
The material doesn’t change the writing system, but it does make a big difference in how it feels in your hand. Aluminum is anodized, lightweight, and the only version available in all eight colors. Titanium is heavier and harder; it comes in matte, polished, or with a dark DLC coating, and is the material for people who want to keep a pen for twenty years. Brass is even heavier and “alive”: its brushed surface darkens over time and develops a patina where your fingers rest. Magnesium is available only for the AEON pencil and is the lightest version, designed for long sketching sessions. And the 24-karat gold AEON features a gold-plated body with a wooden grip—more of a piece of jewelry than a tool—with the same tip mechanism as the aluminum model.
When it comes to choosing a pen, here’s what to consider: If you write a lot and for long periods, stick with aluminum or magnesium. If you consider weight a sign of quality, go for titanium or brass. If you’re giving the pen as a gift, focus on the color, not the material.
Which lead fits in which pencil?
This is where most people make the wrong purchase, which is why I’m summarizing it in a single paragraph. AEON ballpoint pens and PEN models use the same G2-standard ballpoint refill; Stilform sells a version developed with Schmidt Technology in a 2-pack in black or blue, but any G2 refill from a stationery store will also work. The FLOW requires the Schmidt P8127 rollerball refill or the identical P8126 and P8120 refills; it does not fit in any other Stilform pen. The ARC requires the Pilot Juice Up LP3RF; although it is also G2-format, it is a gel refill and does not write cleanly in ballpoint pens; conversely, the ballpoint refill does not fit in the ARC. The INK uses standard cartridges or the included converter, and its nib is a separate replacement part. Finally, the AEON pencil does not have a refill but rather tips: Eternal or Graphite, both of which fit the AEON, AEON Pure, AEON Nano, and all material variants.
- AEON and PEN Ballpoint Pens: Refillable Ballpoint Pens, G2 Standard, 2-Pack
- FLOW Rollerball Pen: Rollerball Refill, Schmidt P8127, 0.6 or 0.7 mm
- ARC Gel Pen: Gel Pen Refill, Pilot Juice Up, 0.3 / 0.4 / 0.5 mm
- INK Fountain Pen: Replaceable Nib, Converter, or Standard Cartridges
- AEON Pencil: Eternal tip or graphite tip, sold in a 3-pack in HB or 2B
Which Pen Style Is Right for Whom?
For notes, lists, and sketches where you might need to erase a line, the AEON pencil with an Eternal tip is the way to go, and if you want to carry it with you everywhere, go for the Nano. For signatures and keeping a pen in your jacket pocket, the AEON ballpoint pen is ideal because it opens with one hand. The PEN is the ballpoint pen for your desk, where the cap doesn’t get in the way and the weight feels comfortable. If you write a lot and want a rich line without having to press hard, the FLOW is the right choice. Small handwriting, planners, and technical drawings are best suited for the ARC with a 0.3 or 0.4 mm tip. And the INK is for people who love ink and are willing to rinse the nib every few weeks.
If you’re giving a Stilform pen as a gift, you can’t go wrong with the AEON aluminum pencil: It needs no explanation, requires no replacement leads for the first year, and works equally well for both right- and left-handed users. All series and materials are listed on the Stilform brand page; additional writing instruments can be found in the “Pens and Markers” category.
Frequently Asked Questions About Stilform Pens
What is the difference between the Stilform AEON ballpoint pen and the PEN?
Both are ballpoint pens that use the same G2 refill. The AEON ballpoint pen has a concealed twist mechanism in the tip and can be opened with one hand. The PEN has a magnetic cap that aligns itself when closed and snaps onto the back of the pen when writing. Weighing 60 g and made of aluminum, the PEN is the heavier of the two pens.
What is the difference between AEON, AEON Pure, and AEON Nano?
All three are aluminum pencils with magnetically interchangeable tips. The AEON features a wood veneer accent on the barrel, while the AEON Pure is the version without wood; both are 134.6 mm long and weigh 27 g. The AEON Nano is the shorter version, measuring 94.9 mm and weighing 23 g. The tips are identical for all three and are interchangeable.
How long does the Eternal tip from Stilform last?
The Eternal tip is made of a non-toxic metal alloy and produces a line similar to that of a 2H pencil. It wears down so slowly while writing that Stilform describes its lifespan as practically unlimited. It never needs to be sharpened. If you want a softer, darker line, you can magnetically switch to the graphite tip in HB or 2B.
Which refill fits the Stilform FLOW rollerball pen?
The FLOW uses the Schmidt P8127 ink roller refill, or alternatively, the identically constructed Schmidt P8126 and P8120 refills. Ballpoint pen refills from the PEN or AEON lines and the ARC gel refill do not fit. After writing, be sure to close the cap completely; otherwise, the tip will dry out.
Which nib should I choose for the INK fountain pen?
For beginners, we recommend the polished steel nib in Fine or Medium. Black steel writes the same way but has a matte finish. Titanium has some flex and provides more feedback from the paper; 14-karat gold is the softest nib. Extra Fine is best for tight handwriting on thin paper, while Broad is ideal for signatures. The nib can be replaced later; all are made by Peter Bock in Germany.
Are Stilform pens suitable for left-handers?
The AEON pencil with an Eternal tip is no problem for left-handers because the metal tip doesn’t smudge. With the ARC, the Pilot Juice Up gel refill is permanent and dries quickly; with the FLOW, Stilform states that the Schmidt refill dries quickly enough for left-handers. With fountain pens, it depends more on the paper and ink; in this case, a finer nib is worth considering.
Neo Abgottspon, One Horizon, Raron. As of September 2026.
