Thanks Drazen! These 2002 porcelain dish stamps are from the 4v set, 'Chinese Pottery of Porcelain - Porcelains from Ruyao Kilns.' This kiln was the largest producer of Celadon, the crackled blue/green glazed ware for Imperial consumption during the Song Dynasty (960-1279). In 2000, excavations revealed 15 furnaces and 2 workshops. With only 70 complete celadon vessels remaining, China is petitioning for the Ruyao kiln to be a UNESCO site.