"7581" tea brick is a numbered tea brick produced by Kunming Tea Factory. It originated in the mid-197s. Kunming Tea Factory selected high-quality and delicious sun-dried raw materials from Yunnan big leaf species, and made it through a unique formula. It is called "the most representative Pu 'er cooked tea". In the mid-197s, "7581" was also called "73 Brick" and "Cultural Revolution Brick". Because the shape was uncertain in the early stage of production, printing, paper materials, fonts, sizes and so on were various and had their own characteristics, so it was easy to identify. The "7581" in the late 197s didn't change much, and its shape was gradually fixed in the 198s, until Kunming Tea Factory stopped production in 1996.

from the above, what the Chinese tea marketer said is true. However, the current Chinese tea is a brand of COFCO, and the quality of tea produced by hair packaging is not neat. I wonder who is making the present Chinese tea brick.