Onggijang refers to the skill of making earthenware pots and jars, or to an artisan with such a skill. Koreans have used earthenware pots and jars for thousands of years.
The place where an earthenware artisan worked was called Onggijeom, which was divided into a workshop and a kiln.
Traditional pots and jars, along with porcelain items, were the main items produced in private kilns. Pots and jars were made after the application of caustic soda to the surface of clay-made objects and putting them through a pre-firing stage. Just 40 or 50 years ago, there were many places selling traditional pots and jars across the country. Their number stood at about 500 when surveys were made in 1968 and 1969. However, they have been pushed aside by their machine-made western cousins.
Traditionally, caustic soda was used as glazing in the production of pots and jars. Recently, it was replaced by a lead oxide named Gwangmyeongdan. With the use of lead glazing, the quality of pots and jars declined and the number of Onggijeom decreased to about 250 by 1984 and to less than 199 by 1989. Stainless steel and plastic goods have pushed traditional pots and jars out of the market.