How to Choose the Right Fountain Pen Nib Size

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Choosing the right nib size is one of the most important decisions when buying a fountain pen. The wrong size can make even the best pen feel disappointing, while the right one transforms your writing experience. Here is everything you need to know.

Standard Nib Sizes

Extra Fine (EF)

Line width: 0.2-0.4mm

The thinnest commonly available nib. Extra Fine nibs are popular for writers with small handwriting, journaling in tight spaces, and writing Japanese characters (kanji) where fine lines are essential. They use the least ink and work best on lower-quality paper.

Best for: Small handwriting, kanji, Hobonichi planners, cheap paper

Fine (F)

Line width: 0.3-0.5mm

The most popular nib size worldwide. Fine nibs offer a good balance between detail and smoothness. They are versatile enough for both everyday writing and more detailed work. If you are unsure what size to get, Fine is always a safe choice.

Best for: General writing, beginners, everyday notes

Medium (M)

Line width: 0.4-0.7mm

Medium nibs provide a richer writing experience with more ink on the page. They showcase ink properties like shading and sheen better than finer nibs. The wider line provides a smoother feel since more of the tipping material contacts the paper.

Best for: Ink enthusiasts, signatures, general correspondence

Broad (B)

Line width: 0.6-0.9mm

Broad nibs lay down a thick, wet line that maximizes ink saturation, shading, and sheen. They feel extremely smooth but use ink quickly and may feather on cheap paper. Great for headings, calligraphy practice, and anyone who loves seeing their ink at full expression.

Best for: Ink showcasing, headings, calligraphy, signatures

Japanese vs Western Sizing

This is the single most important thing to understand about nib sizes:

Japanese nibs run approximately one size finer than Western nibs.

A Japanese Fine writes more like a Western Extra Fine. A Japanese Medium writes more like a Western Fine. This applies to Pilot, Sailor, and Platinum pens compared to LAMY, Pelikan, and Montblanc.

Designation	Japanese Width	Western Width
EF	~0.2mm	~0.3mm
F	~0.3mm	~0.4mm
M	~0.5mm	~0.6mm
B	~0.7mm	~0.8mm

Practical advice: If you like a LAMY Safari in Fine, try a Japanese pen in Medium. If you like a Pilot Metropolitan in Fine, a LAMY Fine may feel too broad.

Specialty Nibs

Stub / Italic

Stub nibs have a flat, rectangular tipping that creates thick downstrokes and thin cross-strokes. They add beautiful character to handwriting without requiring calligraphy skills. The TWSBI Eco in 1.1mm stub is an excellent and affordable entry point.

Flex

Flex nibs respond to writing pressure — press harder for thick lines, use light pressure for thin lines. Modern flex nibs (like Pilot’s FA nib on the Custom 742) offer modest flex compared to vintage pens, but they still add wonderful line variation.

Zoom (Z)

Unique to Sailor, the Zoom nib changes line width based on writing angle rather than pressure. Hold the pen upright for thin lines, lay it flat for thick ones. An innovative nib for artists and adventurous writers.

Posting (PO)

A Pilot specialty nib designed specifically for writing with the cap posted on the back of the pen. The angle is optimized for the higher writing angle this creates.

Waverly (WA)

Another Pilot specialty. The Waverly nib has an upturned tip that makes it smooth at any writing angle. It is extremely forgiving for writers who hold their pen at unusual angles.

Nib Material: Steel vs Gold

Stainless Steel Nibs

Firmer, more consistent writing experience
Less expensive
More durable and resistant to damage
Perfect for beginners and daily beaters
Examples: LAMY Safari, TWSBI Eco, Kaweco Sport

Gold Nibs (14K, 18K, 21K)

Softer, more responsive to pressure
Often described as having more bounce or spring
Higher purity gold (21K) tends to be softer than lower (14K)
A different feel, not necessarily better
Examples: Pilot Custom 823 (14K), Pelikan M800 (18K), Sailor Pro Gear (21K)

Important: Gold nibs are not inherently smoother than steel nibs. A well-tuned stainless steel nib can be just as smooth as gold. The difference is in the feel and flex response, not smoothness.

Our Recommendations by Use Case

Daily journaling: Japanese Fine or Western Extra Fine — compact lines that fit more text per page

Letter writing: Western Medium or Japanese Medium-Fine — a pleasant, readable line that shows off your ink

Ink reviewing: Western Broad or stub — maximum ink on page to evaluate color properties

Note-taking on cheap paper: Japanese Fine or Extra Fine — less ink means less feathering and bleedthrough

Calligraphy and art: Stub, italic, or flex nibs — line variation adds visual interest

How to Test a Nib

If possible, try before you buy. Many pen shops have sample pens available. When testing, write your normal text at your normal speed — do not just draw circles and figure-eights. Pay attention to:

Smoothness — does the nib glide or catch?
Feedback — can you feel the paper? Is it pleasant or annoying?
Wetness — is the line saturated or dry?
Line width — does it match what you expected?
Starting reliability — does it write on the first stroke after sitting?

The perfect nib size is deeply personal. What feels perfect to one writer may feel too fine or too broad for another. Do not be afraid to experiment — that is half the fun of this hobby.