How long will it take Zhang Shun to break the back of the Watergate painting?

Zhang Shun broke the Watergate and painted his back for 9.5 hours. At present, it takes 9.5 hours to draw the full back of Zhang Shun Watergate. Zhang Shun's Watergate Break is a very popular tattoo pattern with a full back in Japan, which originated from the illustration drawn by the Japanese painter Furukawa Guofang for the Water Margin published in Japan. Therefore, most of the tattoos of "Zhang Shun Watergate Break" on the market are Japanese-style, but I am more interested in this story.