Flattened-shaped jars like this one started to appear around the late 13th century. Each of the flattened sides is decorated with an image of a lotus flower pond, enclosed in a lobed panel. The protruding sides, on the other hand, depict an image of bamboo trees and plum blossoms. This particular example seems to have been produced in the late 14th century, when the overall quality of techniques involved in making celadon works sharply deteriorated. In contrast to translucent greenish blue celadon works of the 12th century, this flask has gray greenish glaze due to less refined clay. Furthermore, its rather roughly executed inlaid design shows a clear sign of decline in craftsmanship. Nevertheless, less attention to technical details gave way to a freer style pottery called <em>buncheong</em> in the succeeding centuries.