The ancient calligraphy were originally makimono (scroll) and jo (quire), and they were gradually cut off and stored, then each of them was called "a piece of excellent classical calligraphy."
古筆はもともと巻物や帖であったが、それを切断して収蔵するようになり、それぞれを古筆切（こひつぎれ）と呼ぶようになった。