Bowl, Koryo Dynasty (918-1392). Green glaze. Incised pattern inside. Inlaid black and white medallion outside, 7.3 × 19.1 cm. Purchased with funds from the Libbey Endowment, Gift of Edward Drummond Libbey, 1927.43. © Toledo Museum of Art

Inlaid celadon ware, the outstanding achievement of the Goryeo potters, is almost exclusive to the Koreans. To produce the inlays, an artisan etched the design into the dried clay form and then filled in the incised lines with black or white slip (a liquid clay). The vessel was then glazed and fired in a kiln. On the top bowl, white and black inlays form medallions with two cranes; the bottom bowl features a traditional all-over motif known as the “thousand crane” pattern.