Qinghua Porcelain

Qinghua porcelain (青花, meaning blue-green flower)  is a colouring technique which consists of painting with cobalt oxide based pigment. The finest pieces of qinghua are painted directly on the clay. This technique is called youxia (釉下, meaning 'under the glaze'). In pieces with youlihong, qinghua is painted over a thin layer of glazing (called 釉中, meaning 'inside the glaze'). The qinghua pigment which is initially black-grey, turns into blue during the firing process.