What is "pianwen"

Pianwen (骈文, literally ‘parallel writing’) is a highly stylised prose style, prevalent throughout the history of Chinese literature. Its prominent features lie in its regular lines arranged in couplets; in its early history, these lines were mostly of either four or six characters, and so pianwen are also known as Four-Six Prose .

While the pianwen form was frequently utilised in official writings, or in describing scenery, its tight restrictions in metrical, tonal and thematic terms restricted its literary development. Subsequent movements, such as the Classical Prose Movement, were a response to these restrictions, but pianwen would continue to be written until the end of the Imperial Chinese era and the widespread use of Vernacular Chinese in writing.