Earthenware is divided into ceramics and porcelain, depending on how clay-made objects are baked. An object mixed with white clay and baked at a high temperature is called china or porcelain. Sagijang refers to this skill or to an officially recognized artisan with such a skill.
Ceramics and porcelain, particularly blue porcelain made during the Goryeo Period (877 – 1394) and thereafter are recognized as the best in the world. During the Joseon Period (1392 – 1910), Saongwon (Palace Kitchen Management) was in charge of porcelain production. Its branch in Gyeonggi-do made special objects to be used by the royal family. The government-run porcelain kilns were closed toward the late Joseon Period, following which porcelain artisans started private businesses in Mungyeong, Goisan, and Danyang.
As for the process of china production, first of all, sandy soil is put into water to remove foreign materials. A desired form of is made with the soil, using a foot-operated spinning wheel. The object is then put into a kiln for pre-firing. Glaze is applied to the pre-fired object, and it is again put into a kiln for second firing.
Experts say that grayish-blue-powdered celadon of Joseon evokes a folksy and lively feeling, while white porcelain evokes the character of a gracious scholar.