National Intangible Cultural Heritage, Republic of Korea Nakjukjang refers to bamboo pyrography or artisan with such skill. During the reign of King Sunjo (r. 1800-1834), Park Chang-gyu engaged in the practice, and it was maintained until the colonial period. The practice requires lots of experience and speed. Applications of bamboo pyrography are arrow shafts, acupuncture needle cases, sword handles, folding screens, tobacco pipes, handheld folding fans (particularly thick bamboo pieces forming the first and last sticks), pencil cases, etc. Shapes of butterflies are often used in handheld folding fans, with shapes of bats sometimes used as well. The demand for objects containing bamboo pyrography has decreased noticeably. The skill has been designated as important intangible cultural heritage for protection.