White porcelain jars of this type were produced for about a century -- from the latter half of the 17th century to the early half of the 18th century -- at kilns run by Saongwon (Office of the Royal Kitchens), particularly those in Geumsa-ri, Gwangju, Gyeonggi-do Province. These voluminous round jars with pure, rich character are usually over 40cm high with milky white glaze and are often called moon jars. This jar has height of 43.8cm and diameter of 44cm. The diameters of the mouth and the base are in ideal proportion, giving the vessel a stable appearance. The jar is slightly asymmetric and warped, adding to the overall vibrancy of the vessel form instead of impairing its beauty. The glaze is smoothly melted into the clay. Given their large size, porcelain jars of this style were formed in two hemispheres that were joined together. It was a precarious job requiring deft hands. Firing also called for high expertise. The unassuming aesthetic of these jars typified the porcelain art of the Joseon Dynasty (1392-1910). Most outstanding examples date back to the early part of the 18th century. During the peak years, there were some 340 kilns in the Gwangju area.