The development of curtains has undergone many changes, and the most obvious changes are reflected in the material of the curtains. In the beginning, the window was used only to gouge out or leave a very coarse hole in the wall and ceiling, or a skylight opening of the Indian cone-shaped tent, its basic use is confined to ventilation, which is often obscured by the use of the skin of the beast or the woven fabric of the grass. Hides and mats are the earliest form of curtains, and because of the beauty of mats, this window is spread so far, in the south of the summer, there are family will hang mat curtains, take its cool.
The Han Dynasty Cai Lun invented paper, people began to use paper as a window covering. China's ancient windows are papered paper, the window is very small and very dense: one is to anti-theft, the second is the window is too big window of paper is easy to be blown by the wind.
This kind of paste paper lattice window is very common in the northern dwellings, the paper is called Sorghum paper, white, has a certain thickness and toughness, unless deliberately destroy it, otherwise it is not easily broken.