Porcelain is coveted the world over for its unique properties of low permeability, elasticity, strength, hardness, toughness, whiteness, translucency and resonance. Porcelain's exceptional qualities are derived from a combination of quality materials which allow for a very high temperature (2400°F) in the kiln during firing.
Jingdezhen, the birth place of porcelain, has been epicenter of Chinese porcelain since the Ming dynasty. Utilizing the nearby Kaolin Mountain (高嶺山), Chang River and other resources, craftsmen use traditional techniques passed down the generations. Jingdezhen porcelain is famously described as:
being as white as jade
as thin as paper
as clear as glass
as sweet sounding as a chime
-scholar Wen Zhen Heng (1620)
Bone china, a close cousin of porcelain, originated in the UK as a substitute for porcelain. Bone china derives its name from its ingredients: a combination of bone ash (derived from animal bones), kaolin as well as feldspar. Fired a slightly lower temperature, bone china is easier to produce and less expensive than porcelain.
Produced in Chaozhou, by a single workshop of craftsmen (and craftswomen), Spin's bone china appears whiter in comparison to porcelain. This is in part due to the color of the clay as well as components of the glaze.
Zisha is very rare clay found only in Yixing County, China. With 13 naturally occurring colors, Zisha (meaning “purple clay”) is most commonly found as a rich reddish or purple. Entirely hand built, Zisha wares are prized for their very fine unglazed and slightly porous nature which allows the flavors of the tea to be absorbed into the teapot itself. For this reason a well-aged Zisha teapot is highly valued for how the flavor of the tea will change and evolve.