Wares mostly decorated with greenish glaze made at kilns centered in the Longquan area of southern Zhejiang province. Celadon wares was made here from the Northern Song to the early Qing dynasty according to recent excavation reports, as opposed to an earlier belief that the production ended in Ming. Wares from the same kilns but made before Song, would be termed Yue Wares. Longquan wares was an important export commodity to many South East Asian Countries. Over three hundred kilns great and small were firing in the Longquan kiln complex during the Yuan dynasty and many potters seems to have flead or just migrated while bringing their newly invented kiln "tubular support" technology with them, to the Sawankhalok kiln complex in Thailand. The Imperial patronage of the Jingdezhen kilns, the maritime prohibitions who began during Ming and a lack of good clay reported during the Wanli period, seems all to have contributed to the downfall of the Longquan wares. The clay employed, having a comparatively high iron and titanium content and very varied, produced a grayish body. During the Northern Song the firing temperature used was c. 1180-1200 centigrades, reaching c. 1230-1280 centigrades in the Southern Song period. Color differences occurs depending on how strong the reducing atmosphere was during firing. Bright greenish glaze colors result from high reducing, and grayish glazes from a weak reducing atmosphere. Incised, sculpted, applied, and molded decoration was employed, and a large proportion of the output consisted of export goods, everyday utensils, and imitations of Guan and Ge wares. The Longquan Kilns were rediscovered around the 1930s, when the railway was extended from Shanghai to Hangzhau, and Longquan pieces started to surface. Immitations: Due to its popularity wares similar to "Longquan Celadons" has been produced at other kilns until this day.