This storage jar dates to the late Choson period (1392-1910) and is decorated with a motif of flowers and butterflies in under-glaze copper red. Almost all extant examples of copper-decorated white porcelain date from the eighteenth century or later. Because of the greyish-white glaze and faint blue or green hue, it is believed to have been made in a local kiln. The technique of decorating ceramics with copper-red developed in Korea in the 12th century when it was used on celadon wares, but it was virtually unused in the making of white porcelain until the mid 18th century. Because of the unpredictability of copper, the colour would sometimes blur or turn green or brown after high-temperature firing.