Tead Off wrote:Good choice! Onggi is an overlooked clay.
Great that we share some similar interest. Onggi means vessel, jar or lidded jar. So different area have different clay and glaze. Just so you know.
The word onggi is used in various contexts. I have never seen onggi defined as vessel, jar, or, lidded jar, but within a certain context, it can refer to these things. When I ask Seong il what does onggi mean, he says earthenware. It can also mean the tradition of making earthenware storage jars. These jars, made by onggi potters, use a different technique in building these jars than most other traditions.
The clay used for onggi production is iron-rich clay with a mixture of mud and sand. There are different sources for this type of clay throughout Korea. Not all onggi clays are the same but they share some common characteristics. They are particularly good for aging(fermenting) food because of their mineral structure and firing. The glazing is used to make them waterproof, otherwise, they are too porous.
In Seong il's case, his onggi teaware uses a mixture of stoneware so it can be fired at a higher temperature and glazed with shino. This takes care of the leaking that would occur and gives more possibilities for artistic interpretation and interesting glazing effects.
Hope this helps clarify a bit for those unfamiliar with this tradition/clay/usage. I'm sure I'm leaving lots of details out but just trying for a general explanation.