let's talk about the paperweight, which is a traditional handicraft of Han nationality in ancient China. Refers to things that are used to press paper when writing and painting. Most of them are rectangular strips, which are also called weighing scales and pressure scales for some reasons. The original paperweights were not fixed in shape. The origin of paperweights is that ancient literati often put small bronzes and jades on their desks to enjoy them. Because they all have a certain weight, people will use them to press paper or books while enjoying them. Over time, they have developed into a kind of stationery for study-paperweights. It is known that the earliest mention of special paperweights was in the Southern and Northern Dynasties, "The Ancestral History of the Southern History of Yuan Rong": "The Emperor (Xiao Daocheng, Emperor of Qi Gao, 427-482) tried to use white jade paperweights as a coffin, and iron as a book to make the town happy, and it was very strong, so as to prepare for it, and he wanted to replace the staff."
besides brass, brass is an alloy composed of copper and zinc. The word brass refers specifically to copper-zinc alloy, which began in the Ming Dynasty, and its record can be found in Ming Hui Dian: "In Jiajing, there is an example, Tongbao money is 6 million yuan, and 47,272 Jin of second fire brass is used ..." Through the analysis of the composition of copper coins in the Ming Dynasty, it is found that the appearance of casting brass in the Ming Hui Dian is much later than that of other copper alloys, because it is difficult to obtain zinc in brass. Zinc oxide can be quickly reduced to metallic zinc at a high temperature of 95℃-1℃, while liquid zinc has boiled at 96℃, so the metallic zinc obtained by reduction exists as vapor. When cooling, the reaction is reversed, and the vapor zinc is oxidized into zinc oxide from carbon dioxide in the furnace, so it is necessary to have a special condensation device to obtain metallic zinc. This is one of the reasons why the use of zinc metal is much later than that of copper, lead, tin and iron, and it is also one of the reasons why brass castings appear later. There are very few copper-zinc alloy coins in the money of the Western Han Dynasty and Xinmang, and the content of zinc in some coins reaches 7%, but this does not mean that brass coins were produced at the time of Xinmang in the Western Han Dynasty. Because these copper-zinc alloys are extremely rare phenomena, their zinc content is generally much smaller than that of brass in the real sense, which is 15%-4%. These copper coins containing zinc were produced when copper and zinc were used in the "mountain casting money" in the Han Dynasty. Because one is a very rare phenomenon, and the other is brass, which is still not really meaningful, it is currently recognized that China brass products appeared in the Ming Dynasty.