62g Professional Oil Soot 101 Youyan Chinese Ink Stick Caosugong Inkstick youyan oil soot 101 62g Inkstick for calligraphy and painting. Shanghai Cao Su Gong Ink Shop. Opened in 1864, this shop has produced and sold ink for more than 100 years. And in 1914, Cao Su Gong ink won the gold medal in the Tokyo Expo.