The Eight Principles of Yong are used by calligraphers to practice how to write the eight most common strokes in regular script, using the fact that they are all present in the character 永; yǒng; 'forever', 'permanence'. It was believed that the frequent practice of these principles as such when beginning one's study could ensure beauty in the Chinese calligrapher's writing.
The Eight Principles are influenced by the Eastern Jin-era Seven Powers (七勢) by Lady Wei Shuo. Publications on the principles include:
In addition to these eight common strokes in 永, there are at least two dozen strokes of combinations which enter in the composition of CJK strokes and by inclusion the CJK characters themselves. Many are included in Unicode.[4]
Gallery
The principles, as shown in the Vietnamese book Nhật dụng thường đàm日用常談 (1851), with their individual strokes
A section in Ngũ vân lâu tăng đính tứ thể thư pháp五雲摟增訂四體書法 (1848), explaining the concept of the Eight Principles of Yong
The Eight Principles of Yong depicted the calligraphy book, Tứ thể bút thức四體筆式 (1869)