Understanding Fountain Pen Nib Sizes: From No.4 to No.8 and Beyond
- Burak Şahin
- Oct 8
- 2 min read
In the world of fountain pens, terms like No.5, No.6, and No.8 often appear — but these are not about line thickness.They describe the physical dimensions of the nib unit and feed, determining how the nib fits into the pen body.
In reality, there are more than just three sizes: some pens use No.4, No.7, No.8.5, or even No.9 and No.10 nibs, especially in vintage or brand-specific systems.However, modern handmade pen makers mostly rely on No.5, No.6, and No.8 for their balance, availability, and aesthetic harmony.
🔹 Common Nib Sizes and Their Uses
No.4: Found in small vintage pens and compact models like Kaweco.
No.5: Standard size for smaller or lightweight pens.
No.6: The golden ratio for most handmade fountain pens — perfectly balanced in size and flow.
No.7 / No.8: Used in large, luxury or collector’s pens.
No.9 / No.10: Rare, seen in older Montblanc or Pelikan models.
🔹 Nib Systems by Manufacturer
Manufacturer | Common Sizes | Notes |
Jowo (Germany) | No.5, No.6 | Most popular among handmade pen makers. |
Bock (Germany) | No.5, No.6, No.8 | Used in high-end, metal-bodied pens. |
Schmidt | No.5, No.6 | Reliable, mid-range choice. |
Pilot / Sailor / Platinum (Japan) | Proprietary sizes | Brand-specific, not cross-compatible. |
Kaweco / TWSBI | No.4, No.5 | Compact pen systems. |
🔹 Why Vanagas Uses Jowo No.6
At Vanagas Handmade, we primarily use Jowo No.6 nibs in our pens. There are two key reasons:
Compatibility: Jowo No.6 is the most universally used nib unit among independent makers, allowing easy swaps between Fine, Medium, Broad, and Stub styles.
Proportion: The No.6 size fits handmade pen bodies beautifully — visually balanced and comfortable in hand.
Jowo nibs are manufactured in Germany and are known for their smooth ink flow and reliable performance.That’s why many boutique pen brands — including Vanagas — have adopted Jowo No.6 as their standard system.
🔹 Choosing the Right Nib Size
No.4–5: Ideal for portable pens and smaller hands.
No.6: Balanced, comfortable, and perfect for handmade fountain pens.
No.8+: Oversized, bold pens with strong visual presence.
In the end, nib size is not just a measurement — it defines the soul and balance of a fountain pen.And for most handmade creations, the Jowo No.6 remains the perfect harmony between form, function, and feel.
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