Hang-ari, or jars, show considerable regional variations, and are distinctive in each of the provinces of Gyeonggi-do, Chungcheong-do, Jeolla-do, and Gyeongsang-do. Among the different types of onggi, hang-ari jars show the most distinct regional characteristics. Onggi from the central region, including Gyeonggi-do and Chungcheong-do Provinces, are similar, being slender without a swollen belly, but jars from Chungcheong-do Province are wider than those of Gyeonggi-do. Jars from Gyeongsang-do and Jeolla-do Provinces are distinctive in that their bellies are swollen, although they vary in details. Gyeongsang-do jars have a big belly but the mouth is very small, tapering in rapidly from the shoulder. On the other hand, Jeolla-do jars have a large mouth with a diameter wider than the base, and the upper belly is swollen with wide shoulders and a round body. This feature of Jeolla-do jars, which have a larger capacity, may be related to the area’s fertile fields that produce abundant crops. ---「Chapter 1. Onggi: An Introduction」중에서

The glaze for onggi is an alkaline-based glaze. Wood ash is mixed with water and yakto. Yakto is a form of compost high in iron produced by fungal breakdown of tree leaves and roots. It is mostly obtained in mountainous areas with pine forests. Wood ash is made mainly from pine trees, and usually mixed with yakto in the ratio of 1:1, though it may be adjusted in certain cases. Good yakto melts thoroughly, but when yakto does not fully melt more wood ash is added to lower the fusing point. Onggi are covered with glaze, but jilgeureut and puredogi are not glazed and instead are surfaced with soot. In particular, when puredogi are fired, salt is introduced into the kiln and melts into the surface along with the soot, which creates a thin film and fills in the porous walls performing nearly the same as a glaze. This makes the vessel walls impervious to water. ---「Chapter 2. Materials and Tools for Making Onggi」중에서

The body of the onggi vessel is constructed by repeating the sequence of coiling (or slab-building), paddling and smoothing. When coiling, potters use their fingers to smooth and join the coils above with those below. As for slab-building, the slabs themselves are nearly in the form of the walls, so it only requires connecting them with the adjoining slabs. The first coil or slab on the bottom disk is called a cheong tarim, which means first coil or slab. It is very important to adhere securely the base with the cheong tarim, so clay is added and sealed to the inner area between the base and the coil or slab. ---「Chapter 3. Making Onggi」중에서

Onggi were widely utilized in our daily lives. During winter, family members gathered around an earthenware brazier and had fireside chats after dinner, and earthenware chamber pots were kept in a corner of the bedroom at night time. Onggi tiles were used to construct the roof, and onggi clay was also utilized to make a well or a bath tub. Sarangbang (men’s quarters) were furnished with scholars’ accoutrements including water droppers, ink stones, brush holders, brush rests, tobacco pipes, and spittoons, among others. Onggi clay was also made into beehives, loach traps, octopus traps, fishing net weights, yaknyo bottles, buhang danji, and baemiri. There were also ritual vessels and musical instruments made of onggi clay, including the janggu, wind instruments hun and kkureugi, and a percussion bu. Gansutong, a basin for collecting gansu (salted water) used in making bean curd, and semi-cylindrical shaped pillows filled with hot or cold water for winter and summer days were also made with onggi clay.