How does a nib work? Part 4
In the previous post we looked at The Feed.
Post 4 — Where the River Pauses
Have you ever wondered why the ink in a fountain pen flows right to the tip — and then suddenly stops, waiting until the moment the nib meets paper?
In the last post, we left our river of ink, regulated and calm, flowing towards the nib.
The section cap stands like a gatekeeper at this junction. It keeps the ink reserves safely within the fins, but just as importantly, it locks nib and feed together so their channels line up with perfect precision. Without that alignment, the chain of capillary force could be broken, and the river’s flow might falter.
The slit on the nib lines up with the feed’s central capillary channel
From here, the nib takes control. Its split is finer than the feed channel, which means its capillary pressure is stronger. The ink is drawn out of the riverbed and further accelerated toward the tip. And then, just when it seems ready to spill, the flow comes to a sudden halt.
Why? Because at the very end, the slit widens ever so slightly. This gentle easing weakens the capillary pull and allows a small convex meniscus to form — a natural brake that stops the river from flooding the page. We’re not sure of the formal name but we call it the holding meniscus.
The gorge has delivered and steadied the flow. Now the nib holds it back, until the fibres of the paper draw it forward on the final leg of its journey.
In the next and final post on the nib, we will put it all together and see how one or two features control how the nib feels in the hand.
Click here for a deeper dive into the mechanics.
