There are many types and models of fountain pens. According to the composition of the pen nib, they can be classified into three categories: gold pens, iridium pens, and ordinary fountain pens.

Gold Pens

Gold pen nibs are made of gold alloy. They are soft, highly elastic, and offer a comfortable writing feel. However, gold pens are expensive, and their soft nibs are difficult to control, making them unsuitable for beginners.

Iridium Pens

Iridium pen nibs contain no gold, though some are gold-plated. The nibs are relatively hard, cost-effective, and ideal tools for beginners learning to write.

The reason gold nibs and iridium nibs are more durable than ordinary fountain pen nibs lies in the small round bead on the tip. This bead is made of an iridium-ruthenium alloy, which is extremely hard and wear-resistant. According to tests by Shanghai Jinxing Gold Pen Factory, if a gold nib and an ordinary steel nib are ground on an oilstone simultaneously, after one hour, the gold nib wears only 0.07 millimeters, while the ordinary steel nib wears as much as 5 millimeters.

Although there is a huge price difference, the iridium beads on all high-quality nibs are made of the special alloy of iridium and ruthenium. The difference in smoothness comes from different polishing methods and precision levels. In a sense, gold pens and iridium pens are similar in core writing performance. However, differences in materials and writing feel lead to a significant gap in price.

Ink contains a small amount of sulfuric acid, and even this mild corrosive substance poses a serious threat to fountain pens. If a pen nib is made of ordinary steel, it cannot resist acid corrosion and will not last long. What metals can resist corrosion? The answer is gold, iridium, and stainless steel. Gold is corrosion-resistant, so people use it to make pen nibs. However, pure gold is too soft to be used directly. The nibs of the gold pens we usually refer to are all alloys. High-quality gold pens often have “14K” marked on the nib, indicating 58.8% gold content, plus silver and brass; “12K” means 50% gold content. This combination improves hardness and provides excellent elasticity. The silvery-white bead on the gold nib is called an iridium bead. It is an alloy mainly composed of iridium and other rare metals, making it highly wear-resistant. Writing relies entirely on this bead gliding across the paper, and it must “travel thousands of miles” over its lifespan. Iridium pen nibs are made of stainless steel. Fortunately, the iridium beads on iridium nibs are identical to those on gold nibs. Therefore, iridium pens offer similar writing performance to gold pens but at a much lower price, making them popular for their high cost performance. Ordinary dip pens and fountain pens without inlaid iridium beads have a much shorter service life.

Narrow Definition

In the narrow sense, ordinary fountain pens are similar to iridium pens, as both use stainless steel nibs. The only difference is that iridium pens have welded iridium beads, while ordinary fountain pen nibs do not. As a result, ordinary fountain pens have a much shorter service life than iridium pens and gold pens.