raw material：Select fine particles、high plasticity、Iron rich river mud or sedimentary clay，After repeated washing to remove impurities。

forming：

Mainly using fast wheel drawing technology，Realize regular device shape、Extremely thin tire wall。

Eggshell pottery high handled cup is the ultimate embodiment of wheel making technology。

fire（key steps）：

At kiln temperature900°CLeft and right time，Closed kiln mouth，Add wet firewood or splash water，Create a hypoxic reducing atmosphere。

Iron element in clay（Fe?O?）Reduced to ferrous oxide（FeO），Make the tire body appear black and dense。

surface treatment：

After firing, it is often polished and polished，Make the surface shiny like paint，No need to apply glaze“Bright as a mirror”。

? Black Pottery“Four Wonders”：Black as paint、Bright as a mirror、Thin as paper、Hard as porcelain