Nibs

From WikiPenia for PenBoutique

The nib of the fountain pen is usually made of stainless steel or gold. Gold nibs are tipped with a hard, wear-resistant alloy that typically utilizes metals from the platinum group. Tipping material is often called "iridium", even though hardly any penmakers still use that metal in their tipping alloys. Steel nibs may also have harder tips; those without steel points will wear more rapidly due to abrasion by the paper. The nib will adjust itself more readily to the user's style the more rapidly the nib wears down.

The nib usually has one slit cut down its center, to convey the ink down the nib by capillary action, as well as a "breather hole" of varying shape to promote the exchange of air for ink in the pen's reservoir. The whole nib narrows to a point where the ink is transferred to the paper. Broad calligraphy pens may have several slits in the nib to increase ink flow and help distribute it evenly across the broad point. Nibs divided into three 'tines' are commonly known as 'music' nibs, as their broad line is suited for writing musical scores.

Fountain pens dating from the first half of the 20th century are more likely to have flexible nibs, suited to the favored handwriting styles of the period. By the 1940s, writing preferences had shifted towards stiffer nibs that could withstand the greater pressure required for writing through copy paper to create duplicate documents.