Do you know the key points of buying a ballpoint pen?
1. The high-end ballpoint pen has obvious trademark and model marks on the pen sleeve, and the end of the refill also has obvious brand, production date and "DA" mark ("DA" mark is the first Chinese pinyin of the file. Letter combination).
2. A metal tubing refill must be used. The pen tip ball must be made of cemented carbide-tungsten carbide ball. The writing performance is better than ordinary ballpoint pens. The ink filled in the refill must use fixed-point production of 424 pure blue ink. And 322 black ink. These two kinds of inks have the advantages of light fastness, water resistance and impermeability. Ballpoint pen cores filled with these two kinds of inks can be used for file writing (including plastic tubing refills, but the color of the tubing must be light yellow tubing).
3. On the packaging of goods, there are marks and marks such as trademark, model, name of manufacturer, place of origin and quality inspection certificate. Counterfeit and shoddy goods. The ink filled in the refill is not an archive ink approved by the National Archives Administration. There is no "DA" mark on the refill, and there is no trademark brand, model, factory name, or place of production. Some are smuggled from foreign countries with unlicensed pens. The core is assembled to pretend to be an imported high-end ballpoint pen.