Slip Casting Yixing Teapots

History of Slip Casting in Yixing

The Yixing Zisha Craft Factory (江苏省宜兴紫砂工艺厂, Jiangsu Sheng Yixing Zisha Gongyi Chang)[1] was founded[2] within the Chinese Communist system with the ideological vision of a collectivized craft workshop, suitable for technological development – turning craft into an industry. Yixing was seen as a viable good for foreign-trade, bringing much needed hard-currency[3] into the communist system. As such, the Yixing Zisha Craft Factory[4] was mandated to increase production and reduce costs.

F1’s early attempt at increasing zisha ware production focused on the adoption of slurry molds[5] for slip casting (注漿法, zhu jiang fa), a new method[6] where ultra-fine-milled clay powder is blended with an excess amount of water[7] to create a free-flowing slurry poured into a three-dimensional mold. It is believed that slip casting was first tried as early as F1’s first or second year of production (1955 or 1956 CE); in either case, F1 attempted slip casting from its founding, and by 1958 CE, the technique was a major focus of the collectivized factory.

Originally, each component of the teapot was cast in a slurry-mold and jointed; eventually, it became clear that certain components, including the handle, spout, lid-knob, and occasionally the lid, were faster to construct by hand. These components were built separately and attached to the slurry-mold made teapot body, leaving tell-tale signs of their opposing construction: the slurry-mold body is generally a darker color and smoother texture, with no embedded grains or irregularity in the body’s color. In contrast, the hand-made components will have the color and texture expected of zisha clay.

The slurry molding technique was finally abandoned in Yixing around c. 1960 CE, as the teapots produced cracked during use[8], and overall production volume of wares did not increase.

It should also be noted that many modern low-quality mass-produced slip cast wares are sold as “Yixing teapots” with no connection to zisha material. This chapter, like all chapters in this book, does not attempt to cover fake Yixing teapots made from non-zisha material.