We had a guest who is specialized in Kakejiku and Byoubu, paper scroll and paper screen.
今日は表具屋さんが来てくださいました。
Byoubu has several layers of paper to construct a thic flat surface. This paper, which was used for the foundation, is an old note of math. It seems to be very old as it was written with ink and brush.
壊してもいい屏風を持ってきてくださり、紙を破って構造の中を見ることができました。紙が何重にも重ねられています。よく見ると数学の問題集のようでした。昔の和紙は質がいいので、古い紙をよく使うそうです。