入木三分 — “To penetrate the wood three fen deep”

Wang Xizhi, whose courtesy name was Yishao, was from Kuaiji (present-day Shaoxing, Zhejiang) during the Jin Dynasty. He is China's most renowned calligrapher in history. Because he once served as General of the Right Army, he is also referred to by later generations as Wang Youjun.

Wang Xizhi's calligraphy was exceptionally brilliant, unmatched in ancient and modern times. His characters were elegant yet vigorous, gentle yet strong. No calligrapher in subsequent generations could rival him, and many who learned calligraphy used his works as models. Among his surviving works, the most famous include "Preface to the Poems Collected from the Orchid Pavilion" and "Huang Ting Jing."

Wang Xizhi's exceptional calligraphy was partly due to his natural talent, but most importantly, it stemmed from his diligent practice. To perfect his writing, he constantly pondered the structure, framework, and spirit of characters, whether resting or walking. He incessantly traced characters with his finger on his robes, which eventually wore them out. He once practiced calligraphy by a pond, and after each session, he would wash his brushes and inkstone in it. Over time, the entire pond's water turned black, showing the profound effort he invested in his calligraphy practice.

It is said that he had a great fondness for geese, often gazing blankly at them playing in the river. Later, he even gained insights into brushstroke techniques from the movements of geese, which greatly benefited his calligraphy skills. One time, he visited a Taoist temple and, seeing a group of lovely geese, asked the Taoist priest to sell them to him. The priest, who had long admired Wang Xizhi's calligraphy, requested him to write a copy of "Huang Ting Jing" in exchange. Wang Xizhi, truly captivated by the geese, agreed. So, Wang Xizhi wrote the "Huang Ting Jing" for the temple, and the Taoist priest gave him all the geese.

On another occasion, the emperor of the time was going to offer sacrifices in the northern suburbs and asked Wang Xizhi to write the sacrificial prayers on a wooden board for workers to carve. The carvers were astonished when they worked on the board; Wang Xizhi's brushstrokes had penetrated more than three fen deep into the wood! They exclaimed in admiration, 'General Youjun's calligraphy truly penetrates the wood three fen deep!'