First of all, armor is a means to increase defense in war and an essential military material on the battlefield. The stronger the general armor quality, the stronger the combat effectiveness of the army. In ancient wars, these armor materials were generally made of leather or iron pieces. Most soldiers' armor is made of leather, which is much worse than the general's armor. Armor made of leather has high flexibility and is beneficial for soldiers to fight. Although there are many iron armor in history, the defense has indeed improved, but the flexibility is much worse. Moreover, because the armor made of iron is relatively heavy, the physical consumption of soldiers is too great. Armor is common in western armor, while armor made of pure iron was not common in ancient China. Generally, the armor of senior generals is made of leather and iron, and some necessary fragile parts are protected with iron sheets, which improves the defense ability to a certain extent and does not greatly weaken the flexibility.
Leather armor can resist some sword wounds, and of course it can only be reduced to a certain extent. These injuries cannot be completely avoided, and they are not very effective for some heavy weapons, such as broadswords and strong crossbows. In the Song Dynasty, firearms appeared, and the weakness of leather armor was gradually revealed. At this time, the main materials of armor are iron sheet and cotton, which can effectively reduce the damage of firearms, and cotton can bring a certain buffering effect. Ancient armor has also improved with the changes of the times, but it cannot be separated from raw materials such as leather, iron and cotton.