Est. 2026 · Price: FreeEditor-at-large: The Hedgehog

Stationery Times

Monami Rein Fountain Pen: EF Nib, Cartridges, Size

Compiled from 4 sources; we haven't tested this product ourselves yet. How we research

Quick answer

The Monami Rein is a clear demonstrator fountain pen from Korea with an extra-fine steel nib and a spring-lined cap that Monami says stops the ink drying. JetPens lists it at 135 mm capped and 13 g, taking standard international cartridges or a converter, with one black cartridge included. It sits in our $$$ band.

On this page11 sections
Monami Rein fountain pen in Dandelion drawn to scale at 135 mm capped, with a close-up of its extra-fine steel nib
The Dandelion Rein, 135 mm capped; the clear barrel shows the cartridge.

Product facts

Product
Monami Rein fountain pen, EF (Dandelion)
Brand
Monami
Brand origin
South Korea
Made in
Not stated*
Material
Transparent plastic body and cap, steel nib, metal clip (JetPens)
Price range
$$$$20–75 per pen (multi-packs divided by the count)
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Notes on these facts
  • Made by Monami Co., Ltd.. Country of manufacture not stated: Monami's English Rein page and the JetPens spec sheet (read October 22, 2026) don't state a country of manufacture, and we found no Korean-language Rein page on Monami's site. Check the box. Price: example listing.
  • Price bands are typical US retail, checked October 2026.

Key takeaways

  • Monami sells the Rein with an EF (extra-fine) steel nib only, per its English product page.
  • JetPens lists 135 mm (5.3 in) capped, 122 mm uncapped, 149 mm posted and 13 g empty.
  • It takes standard international short or long cartridges or a converter; one black cartridge comes in the box.
  • Monami says it works with its 12 bottled ink colors and 10 cartridge colors.
  • JetPens' Dandelion Rein had 24 reviews on October 22, 2026, the most of its Rein colors.

What is the Monami Rein fountain pen?

It’s a clear, inexpensive cartridge fountain pen from Korea’s Monami, with an extra-fine steel nib and a two-tone transparent body. Monami’s English page describes a “clear, simple design” and a spring-applied cap for “ink dry protection.”

In the US it’s sold mainly by JetPens, which calls it beginner-friendly. The Dandelion version, light green and yellow, had 24 reviews there on October 22, 2026.

Monami Rein specs

Spec Monami Rein EF
Nib Extra fine, steel (Monami, JetPens)
Length 135 mm (5.3 in) capped, 122 mm (4.8 in) uncapped, 149 mm (5.9 in) posted (JetPens)
Diameter 13.8 mm max, 10.5 mm grip (JetPens)
Weight 13 g empty: 7 g barrel, 6 g cap (JetPens)
Filling International short or long cartridge, or converter (JetPens)
In the box One black cartridge, no converter (JetPens)
Cap Snap-on, spring-loaded cap liner, metal clip (JetPens)
Example item code 2110000002 (Dandelion, per JetPens)
Monami Rein drawn to scale at 135 mm capped, 122 mm with the cap off and 149 mm posted
Capped, uncapped and posted, from JetPens' measurements.

What colors does the Rein come in?

JetPens sells it in Dandelion, Rosebay and Lily, each a two-tone transparent pen with an EF nib. Dandelion pairs a yellow barrel with a light green cap, as in our drawing.

Monami pairs the pens with its own inks: its English page says the Rein works with 12 colors of Monami bottled ink and 10 colors of cartridges.

Which ink cartridges fit the Monami Rein?

Standard international cartridges, short or long, fit, according to JetPens. That’s the most common cartridge size outside Japan, so you can use Monami, Diamine or other international short and long cartridges.

For bottled ink, add a standard international converter, which isn’t included. A long cartridge holds more ink but needs a barrel long enough; JetPens lists both lengths as compatible.

What does the spring-lined cap do?

It keeps the nib from drying out between uses. Monami calls it a “spring applied cap” for ink-dry protection, and JetPens lists the feature as a spring-loaded cap liner, an inner cap that seals around the nib.

That matters with an EF nib, whose fine channel is the first thing to dry and skip after a few days capped.

How does the Rein compare to the Monami Olika?

The Rein is Monami’s clear, sturdier step up; the Monami Olika is its cheaper beginner pen.

Monami Rein Monami Olika
Nibs EF F or EF
Body Transparent two-tone, metal clip Plastic with rubber grip
Cap Spring-lined Plain snap cap
Price band $$$ $$

Against other clear starter pens, the Platinum Preppy costs less and the Pilot Kakuno adds a smiling nib; both use their makers’ own cartridges, while the Rein takes international ones.

Is the Monami Rein good for journaling?

Yes, for small handwriting: an EF nib suits narrow planner lines and thin paper. A finer line puts down less ink, which helps on thin journal paper where a broad nib might show through.

It’s also a light pen. JetPens lists 13 g empty, with 7 g in the barrel and 6 g in the cap, so it doesn’t drag in a pen loop or pocket.

The clear barrel is useful for a daily journal too: you see when the cartridge is low before the pen runs dry mid-entry. If you’d like to match ink to the pen, Monami offers 12 bottled colors and 10 cartridge colors, by its own count.

What it can’t do is line variation. With one EF nib and a firm steel point, the Rein writes an even line, so choose a brush pen or a broad nib for headers.

Where is the Monami Rein made?

Monami doesn’t say. Its English Rein page and the JetPens spec sheet list no country of manufacture, and we found no Korean-language Rein page on Monami’s site, so check the box.

Frequently asked questions

What cartridges fit the Monami Rein?

JetPens lists standard international cartridges, short or long, plus a converter. Monami says it works with its own 10 cartridge colors.

Does the Monami Rein come with a converter?

No. JetPens says one black cartridge is included and no converter, so buy a standard international converter if you want bottled ink.

Can you turn the Rein into an eyedropper pen?

JetPens marks it as eyedropper convertible only with modification, so it isn't a simple swap; use cartridges or a converter unless you know how to seal the threads.

What nib sizes does the Monami Rein come in?

Extra fine only. Monami lists the pen as Rein EF, and the JetPens colors are all EF.

Is the Rein a good first fountain pen?

JetPens calls it beginner-friendly, and the clear body shows how much ink is left. The EF nib suits small handwriting and planners more than bold lettering.

What does the spring in the Rein's cap do?

Monami says the spring-applied cap protects the ink from drying out; JetPens describes it as a spring-loaded cap liner.

Sources (4)

  1. Monami (English site): Fountain Pen Rein EF (transparent body, spring-applied cap for ink-dry protection, 12 Monami ink colors and 10 cartridge colors; read October 22, 2026)
  2. JetPens: Monami Rein Fountain Pen, Dandelion, Extra Fine (MONAMI REIN 2110000002: 13.5 cm capped, 12.2 cm uncapped, 14.9 cm posted, 13 g, 10.5 mm grip, 13.8 mm max; international short and long cartridges or converter; 24 reviews on October 22, 2026)
  3. JetPens: Monami Rein Fountain Pen, Rosebay, Extra Fine (13 reviews on October 22, 2026)
  4. JetPens: Monami Rein Fountain Pen, Lily, Extra Fine

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