https://purengom.com/2017/10/19/%ec%99%80%ec%bd%a4-bamboo-ink-%ec%a2%8b%ec%9d%80-%ea%b7%b8%eb%9f%ac%eb%82%98-%eb%82%b4%ea%b2%8c%eb%8a%94-%eb%8f%bc%ec%a7%80%eb%aa%a9%ec%9d%98-%ec%a7%84%ec%a3%bc/