However, the production of raw silk threads increased in Japan; therefore, the importance of importing raw silk threads decreased; (the function of the new itowappu system included to protect the raw silk threads made in Japan as well as to limit the amount of raw silk threads to be imported to Japan.)
が、日本国内における生糸の生産が増加し、輸入生糸の重要性（新しい糸割符制度は日本国内産生糸を保護と生糸の輸入制限の意図を兼ね備えていた）が低下した。