Blue and white pottery

"Blue and white pottery" (Chinese: 青花瓷; pinyin: qīng-huā cí; lit. 'Blue flowers/patterns') covers a wide range of white pottery and porcelain decorated under the glaze with a blue pigment, generally cobalt oxide. The decoration was commonly applied by hand, originally by brush painting, but nowadays by stencilling or by transfer-printing, though other methods of application have also been used. The cobalt pigment is one of the very few that can withstand the highest firing temperatures that are required, in particular for porcelain, which partly accounts for its long-lasting popularity. Historically, many other colours required overglaze decoration and then a second firing at a lower temperature to fix that.

The origin of the blue glazes is thought to lie in Iraq, when craftsmen in Basra sought to imitate imported white Chinese stoneware with their own tin-glazed, white pottery and added decorative motifs in blue glazes. Such Abbasid-era pieces have been found in present-day Iraq dating to the 9th century AD, decades after the opening of a direct sea route from Iraq to China. According to Jonathan Bloom, these 9th and 10th century Iraqi examples were the first blue-and-white wares. This technique was transmitted to Europe during the Arab conquest of Spain and North Africa and is also believed to have influenced Chinese ceramics through the activities of Muslim traders. The influence of Islamic pottery can be clearly seen in the work of Gongxian potters when they switched to making stonewares for use in daily life. Instead of drawing from the typical repertoire of Tang ornamentation, their angular lozenge motifs and palmettes look like a direct take on Mesopotamian quatrefoil panels filled with Arabic writing and surrounded by leaf fronds.

In China, a style of decoration based on sinuous plant forms spreading across the object was perfected and most commonly used. Blue and white decoration first became widely used in Chinese porcelain in the 14th century, after the cobalt pigment for the blue began to be imported from Persia. It was widely exported, and inspired imitative wares in Islamic ceramics, and in Japan, and later European tin-glazed earthenware such as Delftware and after the techniques were discovered in the 18th century, European porcelain. Blue and white pottery in all of these traditions continues to be produced, most of it copying earlier styles.

Cobalt blue glaze became popular in Islamic pottery during the Abbasid Caliphate, when the cobalt was mined near Kashan, Oman, and Northern Hejaz. In early periods, Chinese craftspeople used blue-and-white porcelain to replicate the styles of Islamic pottery and metal crafts. For instance, Chinese potters in the eighth century duplicated designs like lotus scrolls and motifs from Persian silverwork.

The use of cobalt as an underglaze color was introduced to China from Iraq, where Abbasid potters had been using it on white glazed earthenware since the 9th century. In China, it was first applied to earthenware during the Tang dynasty (618–907 CE) and subsequently to porcelain. Shards of blue-and-white porcelain from the late Tang dynasty have been discovered at the Huangye and Baihe kiln sites in Gongyi, Henan Province. Tang period blue-and-white is more rare than Song blue-and-white and was unknown before 1985. The Tang pieces are not porcelain however, but rather earthenwares with greenish white slip, using cobalt blue pigments. The only three pieces of complete "Tang blue and white" in the world were recovered from Indonesian Belitung shipwreck in 1998 and later sold to Singapore. It appears that the technique was forgotten for some centuries.

Textual and archaeological evidence suggests that blue-and-white wares may have been produced during the Song dynasty, although the identification of Song dynasty blue-and-white pieces remains the subject of disagreement among experts.

In the early 20th century, the development of the classic blue and white Jingdezhen ware porcelain was dated to the early Ming period, but consensus now agrees that these wares began to be made around 1300–1320, and were fully developed by the mid-century, as shown by the David Vases dated 1351, which are cornerstones for this chronology. There are still those arguing that early pieces are mis-dated, and in fact go back to the Southern Song, but most scholars continue to reject this view.

In the early 14th century, mass-production of fine, translucent, blue and white porcelain started at Jingdezhen, sometimes called the porcelain capital of China. This development was due to the combination of Chinese techniques and Islamic trade. The new ware was made possible by the export of cobalt from Persia (called Huihui qing, 回回青, "Islamic blue" or "Muslim blue"), combined with the translucent white quality of Chinese porcelain, derived from kaolin. Cobalt was so prized that manufacturers in Jingdezhen considered cobalt a precious commodity with about twice the value of gold. Motifs also draw inspiration from Islamic decorations. A large portion of these blue-and-white wares were then shipped to Southwest-Asian markets through the Muslim traders based in Guangzhou.