What brush was used to write Wang Xizhi's Preface to Lanting? What are the specifications and sizes of brushes?

According to legend, Wang Xizhi wrote Preface to Lanting with moustache and cocoon paper. Eight-character pen is a kind of writing brush. (1) a brush made of mouse beard. The "mustache pen" in Ci Yuan reads: "A pen made of mustache". Some curious people who studied ancient methods once bought moustaches from eastern Guangdong at a large price and made them into pens. After use, they are as strong as rabbit hair. (2) that is, the pen made of squirrel beard. Li Mingzhizhen's Compendium of Materia Medica said: "The so-called world's food, Sorreltail also." It's not made of a moustache. The parallel brush began in the Han Dynasty. At that time, calligraphers Zhang Zhi and Zhong You used moustache pens. Inspired by this, Wang Xizhi, a sage in the Book of Jin, grew a moustache and wrote a peerless masterpiece "Preface to Lanting". The moustache pen is quite strong and sharp, comparable to a mane. Nowadays, the method of making moustache pen has been lost. The moustache pens sold in the pen shop are all made by Zibo, which has existed in name only. The law book should record: "Wang Youjun wrote the preface to Lanting with a mustache, and the calligraphy of the right army was handed down from generation to generation with a mustache left by Mr. Baiyun." Wang Xizhi's Calligraphy Classics: "According to legend, Zhang Zhi and Zhong You used eight-character pens, and their strokes were vigorous and sharp." "Dongpo Inscription and Postscript": "Inscription on the Moon Tower makes paper, brush and Li Tinggui ink all temporary choices." The Lanting Collection written by He in Tang Dynasty: Preface to Lanting written by Wang Xizhi with moustache and cocoon paper. That moustache pen, or that pen that has been lost, is not made of moustache. Or think it's a wolf's brush Cocoon paper, paper made of cocoon shell, white and meticulous. Volume 15 of Fu Lun Shi is quoted from Shi Shuo Xin Yu by Liu Yiqing in the Southern Song Dynasty: "Wang Xizhi's book Preface to Lanting uses cocoon paper and a pen to strengthen the body with charm, which is even more unique." Hao Yixing's "Prove Custom" in Qing Dynasty, Volume 7: "If it is ancient paper, there are edge paper and cocoon paper. Shi Shuo is like a cocoon made of paper, which is used in Wang Youjun's Lanting Collection. This box is made of Korean paper. " Some people think that this kind of paper does exist in history and is made of animal fiber-silk. Others think it doesn't exist at all; It has also been suggested that it was originally made of plant fiber-Broussonetia papyrifera bark, which was misunderstood because of its white appearance like silk.