However, with improvement made in the Northern Song Dynasty Period, chikushi paper became stronger, which Wang Anshi and Su Shi (Chinese poet) favored because of its gloss, color development of sumi ink and color retention.
だが、北宋時代に改良が加えられてより丈夫になり、また王安石や蘇軾がその光沢や墨の発色ぶりと保色性を高く評価してこれを寵愛した。