Pen tip size — those little numbers like 0.38, 0.5, and 0.7 — quietly shapes how your journal looks and feels to write in. Pick the right one and your handwriting looks its best with no bleed; pick wrong and letters fill in or ink soaks through. Here’s how to choose.
What the numbers mean
For gel, ballpoint, and rollerball pens, the number is the line width in millimeters — roughly how wide a stroke the pen lays down. Smaller numbers mean finer lines. Fineliners use a similar scale (a Micron “01” is about 0.25 mm). Fountain pens use nib labels instead — EF (extra fine), F (fine), M (medium), B (broad) — and Japanese nibs run finer than German ones at the same label.
Tip size by use case
| Tip size | Best for |
|---|---|
| 0.28–0.3 mm | Very small handwriting, detailed bullet journaling, tight notebook lines |
| 0.38 mm | Neat, small-to-medium handwriting; the enthusiast favorite |
| 0.5 mm | The all-purpose default — comfortable for most people |
| 0.7 mm | Larger handwriting, faster writing, a bolder line |
| 1.0 mm / Medium nib | Big, expressive writing, signatures, headers |
Tip size and bleed-through
Here’s the hidden benefit of a finer tip: it lays down less ink, so it bleeds and ghosts less. If you’re fighting bleed-through on thin paper, dropping from 0.7 mm to 0.5 or 0.38 mm often helps as much as changing pens. More on that in why pens bleed through paper.
The safe default
If you’re unsure, start at 0.5 mm. It suits the widest range of handwriting and paper. Go finer (0.38 or 0.28 mm) if your writing is small or you want to fit more on a line; go broader (0.7 mm+) if you write large or like a bold look. Ready to choose a pen? See our best fine point pens or the overall best journaling pens.