Wang Yi-mei of Fujen's GITC says that these originally extended down to the knees, and later evolved first into formal jackets long in the back and short in front, and then to equivalent length front and back. The modern form of the Western suit was basically settled by the 19th century.
輔仁大學織品服裝系講師王怡美指出，由長度及膝演變成類似小禮服或燕尾服的前短後長、再變成前後長度一致，十九世紀時，現代男士西裝的樣式已經大致底定。