Baby’s Bottom in Fountain Pens: Causes, Symptoms & How to Fix It
What Is “Baby’s Bottom” in a Fountain Pen Nib?
“Baby’s Bottom” is a nib defect caused by over-polishing during the finishing process. Instead of the tipping material having a flat or slightly squared writing surface, the inner edges become overly rounded, resembling—hence the name—the curved shape of a baby’s bottom.
While the nib may feel extremely smooth on paper, the problem lies beneath the surface.
Why Does Baby’s Bottom Cause Writing Problems?
A fountain pen writes when ink flows from the feed, through the nib slit, and onto the paper via capillary action. When a nib suffers from Baby’s Bottom:
The ink cannot consistently touch the paper
The nib loses proper contact at shallow writing angles
Ink flow becomes interrupted
This often results in:
- Hard starts (especially after uncapping)
- Skipping while writing
- Poor performance with light pressure
- False impressions of ink or feed issues
Ironically, the smoother the nib feels, the worse the issue can be.
Common Signs Your Pen Has Baby’s Bottom
Yes. Professional nib tuning is the safest and most effective solution. A trained nib specialist carefully reshapes the tipping to restore proper ink contact without sacrificing smoothness.
Final Thoughts
A well-tuned nib balances smoothness with reliability. At The Pen Lounge, we encourage writers to view nib tuning not as a repair—but as an enhancement to the writing experience.
What Causes Baby’s Bottom?
Baby’s Bottom typically occurs during manufacturing or nib tuning, when:
The nib tipping is polished too aggressively
Rotary polishing wheels remove too much material
Final quality checks focus on smoothness over ink contact
It can occur in both steel and gold nibs, and across entry-level and luxury pens alike.
Can Baby’s Bottom Be Fixed?
Yes—but with care.
Professional Nib Tuning (Recommended)
A skilled nib technician can:
Reshape the tipping material
Restore proper ink contact
Preserve smoothness without sacrificing performance
At The Pen Lounge, we strongly recommend professional adjustment to avoid permanent damage.
DIY Fixes (Not Advised for Beginners)
Some experienced users attempt:
Micro-mesh or mylar film polishing
Controlled flattening of the inner tipping edges
However, improper technique can worsen the problem or ruin the nib entirely.
How to Prevent Baby’s Bottom Issues
While you can’t always control manufacturing, you can reduce risk by:
Buying from trusted pen retailers
Testing nibs before purchase when possible
Avoiding excessive pressure while writing
Seeking professional nib tuning instead of aggressive polishing
A properly tuned nib should be smooth, reliable, and consistent—not just smooth.
Final Thoughts
Baby’s Bottom is a reminder that fountain pens are precision instruments. Smoothness alone does not guarantee performance. Understanding nib behavior empowers you to diagnose issues accurately and enjoy your writing experience to the fullest.
At The Pen Lounge, we are passionate about helping writers build lasting relationships with their pens—through knowledge, craftsmanship, and care.If your pen isn’t performing as it should, the nib may just be asking for a little expert attention.