Editing Fountain pen (section)

===Capillary action===
The nib usually has a tapering or parallel slit cut down its centre, to convey the ink down the nib by [[capillary action]], as well as a "breather hole" of varying shape.<ref name="Binder Nibs I"/> The breather hole's intended function is to allow air exchange with the ink reservoir through the channels of the feed, though some modern authorities believe this is a misconception and such venting is unnecessary. Some fountain pens come without a breather hole such as the Camlin Trinity, Monami Olika, Pelikan Pelikano, and Platinum Preppy. The breather hole's other main function is to provide an endpoint to the nib slit and an indexing point for slit cutting. The breather hole also acts as a [[Stress concentration#Prevention|stress relieving point]], preventing the nib from cracking longitudinally from the end of the slit as a result of repeated flexing during use.<ref name="explain" />

The nib narrows to a point where the ink is transferred to the paper. Extremely broad [[Western calligraphy|calligraphy]] pens may have several slits in the nib to increase ink flow and help distribute it evenly across the point, but such designs are more commonly found on dip pens. Nibs divided into three 'tines' are commonly known as music nibs. This is because their line, which can be varied from broad to fine, is suited for writing musical scores.<ref>{{cite web|last1=Binder|first1=Richard|title=To the Point: Making Music with a Pen|url=http://www.richardspens.com/?page=ref/ttp/music.htm|website=Richard Binder's Pens|access-date=26 July 2016|archive-date=14 May 2016|archive-url=https://web.archive.org/web/20160514013226/http://www.richardspens.com/?page=ref/ttp/music.htm|url-status=live}}</ref>