Originally, only people at daijin (minister) or higher positions were allowed to use atsubitai, but after the end of the Heian period, the role of atsubitai had changed and they became caps simply for elder people.
厚額は本来大臣以上にのみ許されていたものであるが、平安時代末期以降は単に年長者用の冠へと位置づけが変化した。