Early earthenware from the Three Kingdoms period is characterized by the jar's gray hue. Closed kiln chambers built on hillsides, which fired clay as high as 2000°F, maintained a low level of oxygen saturation. The loops on its round shoulder suggest that the jar once had a lid fastened by cords. The function of this type of large jar remains unknown, yet it is highly possibly that it was used to store harvested grains and seeds. The pounding technique (tanal in Korean) used to treat the surface strengthened the clay body.