Cizhou Kiln was a large kiln system with numerous kilns in the northern China of Song and Yuan period. It provided various products with different decorative methods, which reflects the distinct features of the age and the colorful folkways culture at that time. The porcelains produced by Cizhou Kiln have been collected by large museums, both at home and abroad. The noticeable feature of this porcelain is that it develops the texture and function of the clay as possible as it can. The black and white porcelain is most famous in this kiln. The colors of white and black, which imply the day and night, are the everlasting colors in natural world. Since Song and Yuan, poems were written on the porcelains. Black and white colors complement the decoration, which looks fashionable and classical. The black and white porcelain has a long history and is popular here and there.  
This bottle with bulge body and flower-shaped mouth is the classical porcelain in the period of Song and Jin Dynasty. The clay of the body is off-white and the lines on it are achieved by skiving. The bulge lines are paralleled, which is full of the sense of rhythm. Then cover them with glossy black glaze. In the process of production under high temperature, with the freely flow of the glaze, the end of the bulge parts for the lines will present the natural color of the clay—-off-white, which is the popular method to produce porcelain in Cizhou Kiln. The line is the unique decoration and the most creative techniques. Apart from the method of skiving, there is another method to achieve the lines. The same type of porcelain is the black glaze white vase with flower-shaped mouth produced by Cizhou Kiln in Jin Dynasty (Picture 1) which is collected by the Tokyo National Museum. The white slurry heap up at the surface of the body achieves the effect of black and white existing together.             
The flower-shaped mouth design of this bottle was evidently affected by the gold and silver wares. Such simulation requires advanced techniques. Firstly, the raw materials must be suitable with strong plasticity and stability, which must be well handled, for they are often contrary. Secondly, in the production process, pay attention to the saggar burning, the position of kiln, and temperature for burning, and so on. The deformation with different degree for this kind of bottles is cause by the hand-made process, which is different from present processing with machine, and changes during the production process. Those are important basis for distinguish the real or fake porcelain.
This type of bottle with lines is not popular. Only the black glazed bottle with flower-shaped mouth produced by Cizhou Kiln in Jin Dynasty, which is collected by Tokyo National Museum (Picture 2), shares the same method to skive lines with this bottle.

Picture 1  Black glazed white vase with flower-shaped mouth produced by Cizhou Kiln in Jin Dynasty  Height：20.2cm

Picture 2 Black glaze bottle with flower-shaped mouth produced by Cizhou Kiln in Jin Dynasty        Height：33.6cm