Karato mask

...From the Heian period onwards, the corners of square pillars were rounded off to create a surface, but the size of the surface became smaller as time went on, from around one-fifth (the measurement of the front of one side divided by the width of the pillar) in the Heian period to around one-twelfth to one-twentieth in the Edo period. This is called a kiri surface, and from the Momoyama to Edo periods, karato surfaces (rounded surfaces rather than straight, with edges on both ends) appeared, and then kichou surfaces (rounded surfaces of karato surfaces sharpened by straight lines). Hexagonal and octagonal pillars are used in hexagonal and octagonal halls, respectively. ...

*Some of the terminology used to refer to "Karato masks" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…方柱は平安時代以降，角を落として面（めん）をとるが，そのとり方は時代が下ると小さくなり，平安時代は5分の1前後(片方の面の見付の寸法を柱幅で除した割合)であったものが，江戸時代では約12分の1ないし20分の1前後となる。これを切（きり）面というが，そのほかに桃山から江戸時代には唐戸（からと）面(直線ではなく丸い面で，両端に決りが付く)をとるものが現れ，さらに几帳（きちよう）面(唐戸面の丸い面を直線で尖らせたもの)へと進む。六角柱，八角柱はそれぞれ六角円堂，八角円堂に用いられる。…

※「唐戸面」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報