In Chinese: Qinghua ("Blue-green decoration"). Porcelain decorated with cobalt on a white porcelain body covered with a clear colorless glaze. Famous from the Mongolian Yuan dynasty (1279-1368) mostly made in the city of Jingdezhen, located on the southern bank of the Chang River in Jiangxi Province. The first underglaze-cobalt ware known so far, was made by kilns at Gongxian in Henan province during the Tang dynasty.
During the Ming Dynasty (1368-1644), the finest blue was imported to China and known as "Mohammedan" blue. It was made throughout the Ming Dynasty, the high points being the reigns of the emperors Xuande (1426-35) and Chenghua (1465-87). By the 17th century, China was exporting to the West, through the various East India Companies of Holland, England, Sweden, and so on.
The Chinese technique in the production of blue and white was to apply the decoration directly on the unfired clay body of the pieces while in other countries it was first hardened in a kiln. The blue is mixed with water and applied with a brush, then the porcelain is glazed and fired in the kiln. It is thought that the supplies of Mohammedan blue to China were low in the reigns of the emperors Chenghua (1465-87) and Wanli (1573-1620). The blue and white of the Qing Dynasty emperor Kangxi (1662-1722) is considered to be of the finest technical workmanship.
With the export to Europe of Oriental porcelain, blue and white became highly prized. When Böttger made his discovery of porcelain making at Meissen in 1707-9, it was Chinese porcelain (and stoneware) that was his inspiration. Although Meissen was not successful with blue-and-white at the outset, when the factory did conquer the technique it produced its famous "Onion" pattern, based on a Chinese design and still made today. When English firms started making soft-paste porcelain nearly 40 years later, again it was blue-and-white Chinese porcelain that was the inspiration. The Worcester Porcelain Co. made both hand-painted and printed designs, inspired by the Chinese patterns and chinoiserie that were the European idea of "Oriental". All the other English porcelain factories, as well as many Continental factories, did likewise. In the 19th century when the myriad Staffordshire factories were "potters to the world", blue and white printed wares were an important part of their production. Both painted and printed patterns were used on pearlware, stoneware, ironstone china, and earthenware.
In the 17th and 18th centuries Oriental blue and white porcelain was highly prized in Europe - it was enhanced by fine silver and gold mounts, collected by kings and princes, and thought worthy of being treated as a diplomatic gift. By the 19th century, it was copied in Europe and not only used in much lowlier surroundings, but also exported all over the world. In the 20th century divers have recovered huge numbers of cargoes of blue and white porcelain that has sunken over the centuries. This porcelain has become important collector's items not the least because their importance for dating Chinese porcelain made for the commoners and the export markets (Minyao).