This book expresses the true essence of Chinese calligraphy.
Tips
memory
髓 means 'marrow' — the core hidden inside bone. So 真髓 = 'the true marrow', the irreducible core. Synonyms: 精髓 (jīngsuǐ — most common), 真谛 (zhēndì — for abstract truths). 真髓 has a slight Japanese-loan flavor (真髄 shinzui).