"Spirit of the Brush" (bǐyì) is central to Xieyi, emphasizing the unique expressive quality and energy that emanates from the brushstrokes, reflecting the artist's inner state, personal vision, and technical mastery, with each brushstroke imbued with intention, life, and a sense of spontaneity.
'Yi' is a central concept in Xieyi painting, referring to the inner intent, meaning, and spirit that the artist aims to convey, emphasizing intuitive expression, suggestive imagery, and the viewer's active participation in interpreting the artwork.