CHANGSHA WARES
Changsha kiln also termed Tongguan kiln is a famous Southern China Tang Dynasty kiln. Based on archaeological records, Changsha wares were developed from the foundations of the Yuezhou wares (ÔÀÖÞÒ¤) (not to be confused with (Ô½Ò¤) Yue wares, same pronunciation but different character), a Tang celadon ware of Hunan. Both were mentioned in the Tang poet Lu Yu treatise on tea with Yue wares of Zhejiang rated the best.
Changsha wares are usually associated with the painted brown and green motifs or appliqu¨¦ designs vessels covered by a straw colour transparent glaze. The colour of the glaze actually ranges from varying tone of straw colour to a creamy yellowish white. The glaze surface ranges from a transparent brightness to a somewhat cloudy finish. A white slip is usually applied to conceal the coarse body before the glaze is applied on the vessel. The glaze has a tendency to peel off from portions of the vessels especially those with the brown glaze. The glaze usually have minute crazings over the surface.
The paste is usually grayish in tone but examples with buff or varying brick colour tones could also be found.
Polychrome decoration
The Tang period is usually associated with production of monochrome white wares in the North and celadon wares in the South. The Tongguan potters were the pioneers in successfully introducing high fired polychrome decorations. Hence, Changsha wares held an important place in the development of chinese ceramics. The colours were produced by mixing lime-glaze with copper or iron oxides. These new coloured glazes were splashed, trailed, brushed and painted on the vessels which were first covered with lime glaze. By firing the wares under oxidising atmosphere, copper oxide glaze turns green, and iron oxide amber-brown or purple-brown with a manganese-iron pigment. There were some rare successful examples of copper red which could only be produced in reducing atmosphere.
In addition to the transparent lime glaze, changsha wares also used a milky-white lime glaze. According to Nigel Wood, such glaze "is rich in oxides of phosphorous and low in alumina that separated in cooling into immiscible glasses. These glass-in-glass emulsions scattered white light and gave the glazes a milky cast. The white and creamy glazes of Tongguan made excellent light-coloured grounds for decoration in trailed green, brown and purple brown". A good example would be the above ewer with trailed polychrome glaze.
Usually when the copper oxide glaze is applied on the milky white glaze, it gives a mouldy green hue. However, sometime a mouldy bluish green hue is produced. This is a form of optical blue and not to be confused with actual blue produced by cobalt.
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| Tang Changsha jar with geometric motif in Shanghai Museum |
Painted motifs
The Tongguan potters successfully applied the iron brown and copper green pigments to paint a wide variety of motifs, such as calligrapy, flowers, fish, children playing, birds,landscape, abstract looking motif and etc. Many of the motifs showed buddhist and Islamic influence.
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Applique Motifs
The second techniques involved the application of darkish brown glaze, often over the limited area of molded decorations luted onto ewers. The molded elements included palm like tree, paired birds, lions, human motif, pagoda and etc.
Polychrome motif, underglaze or overglaze ?
Currently, there is still no consensus on whether the polychrome decoration on changsha is underglaze or overglaze. Prof. Zhou ShiRong, an expert on Hunan ceramics, is of the view that the motifs are underglaze based on physical inspection of the shards. Extensive study by Prof Zhang Fu kang of the Shanghai Institute of Ceramics showed that the designs on Changsha wares are mostly coloured glaze applied over the transparent glaze. According to him this is obvious when examining the cross section of Changsha samples. They do not show traces of the pigments on the surface of the body as oppose to those found on the under-glaze cizhou or early blue and white decoration. Typical underglaze ware has a layer of transparent glaze above the pigments but this is not found on Changsha painted wares. For Changsha wares, the pigment could be seen on the top and mid layer of the glaze but not on the under-layer. Some western scholars term them as in-glaze colours.
More information on Changsha wares
For more on changsha wares in the belitung shipwreck and a survey of Changsha wares, please view below videos:
Belitung shipwreck artifacts video
Appreciating the beauty of Tang Changsha wares (new 16 Mar 09)
For more information on Changsha wares, please read below article by Mr Lim Yah Chiew:
Copyright by: NK Koh (11 Mar 2008)