A pen consists of a pen tip, a pen tongue, a pen holder and a water storage tube for holding ink in the pen holder. Pen tips made of metal are usually divided into three types: those containing gold, those with iridium particles welded on them, and those without gold iridium particles. The tongue of the pen is tongue-shaped, and there is a primary water tank on one side near the pen tip, which is connected with the water storage pipe in the pen holder through a thin tube. The nib is usually made of hard plastic. The pen holder consists of an upper part and a lower part, both of which are tubular. The upper part is a pen cover, which protects the pen tip and prevents the ink from evaporating. Usually made of hard plastic or metal. The "water storage pipe" at the lower part of the pen holder is usually made of soft plastic or rubber. Among the above components, the nib is the most important part of the pen. According to the different materials used to make the nib, pens can be divided into: (1) gold pens. It is made of gold and silver alloy or steel. Gold nib has good elasticity and corrosion resistance. Writing with a golden pen is comfortable and powerful, but it is more expensive. (2) Iridium pen. That is, the nib is welded with iridium particles. The nib has strong wear resistance, good hand feeling, elasticity and corrosion resistance second only to the gold pen, and the price is not expensive. (3) Ordinary pen. That is, a pen with a nib containing no gold and no iridium particles. This kind of pen is easy to wear and has poor elasticity, which is rarely seen in the market. How to choose a pen? One is "look". See if the nib is straight. Take the iridium pen as an example: it mainly depends on whether the iridium particles are symmetrical. The second is "trial writing". Write on paper with a pen tip to see whether it is smooth and comfortable, even in water, whether the writing lines are symmetrical. For beginners of hard pen calligraphy, an ordinary iridium pen will do. At present, there are also craft pens with a certain radian on the market, whose function is to write the change of stroke thickness. A beginner practicing hard pen calligraphy should not practice with this pen from the beginning. With a good pen, you should also pay attention to the correct use and maintenance. Hold the pen correctly when using it (the next section is devoted to it); Be sure to tighten the pen sleeve after use to prevent the pen tip from being damaged and the ink from evaporating and condensing, which will cause the pen path to be blocked or blocked. In addition, after the pen is used for a period of time, it should be cleaned once to keep the waterway clear.