The printed book appeared in a variety of forms during the course of its history in China. These included, among others, the “whirlwind” binding (xuanfeng zhuang), sometimes called the “dragon scales” binding (longlin zhuang), to describe the overlapping sheets of paper within the book; the “fold” binding (zhezhuang), also known as the “folding sūtra” binding (jingzhe zhuang) or “Sanskrit” binding (fanjia zhuang), given its common use in the presentation of Buddhist texts; the “butterfly” binding (hudie zhuang), whose appellation derives from the effect of fluttering papers that accompanies the opening of the book; and the “thread” binding (xianzhuang), a technical designation that refers to the silken or cotton filaments used to stitch together folded sheets of paper into fascicles. (For diagrams of these fabrications, see Fig. 30.).