Is the 20 13 Lanting Preface envelope valuable? Stamp 9 yuan

20 13 Lanting Preface Envelope, stamps are collectible. Preface to Lanting is one of the special stamps of China Ancient Calligraphy-Running Script issued by China Post on May 10. The materials are provided by the Forbidden City in Beijing, designed by Wang and printed by Beijing Stamp Factory. In 353 AD, Wang Xizhi, a scholar of Jin Dynasty, wrote a preface to the collection of Lanting, the best running script in the world, at the foot of Zhu Lan Mountain in Shaoxing, Zhejiang. This set of stamps is also the first set of Xuan paper stamps issued by the State Post Bureau.