Xuan writing brush Xuan writing brush Xuan writing brush or Xuanbi (), is a type of ink brush made in Anhui Province, China. Xuan brushes are often mentioned together with the famous Xuan paper - a kind of writing paper (rice-paper). The ink brushes are normally made in Jingxian County (currently Jing County) of Anhui Province. In ancient times, Jingxian County was under the jurisdiction of Xuanzhou Prefecture (宣州府; Xuān-Zhōu Fǔ; currently Xuancheng), so its name bears the character "Xuan" (Xuān). The Xuan brushes gained popularity in Jin Dynasty (256-420) among classic scholars, governmental officials, calligraphists and painters. During the Tang Dynasty (618-907)
Paper popper Paper popper A paper popper is a party prank that is commonly practiced in public schools. There are many variations of a paper popper, but they all involve a folded sheet of paper being gripped and thrust down. This causes air to be forced into the paper's folded flaps, making the paper flaps pop out in the opposite direction at a high velocity, thus making a loud popping noise. According to popular misconception, the sound is supposed to be caused by the paper breaking the sound barrier. What actually happens is that air rushes in a blast wave to fill