Content deleted Content added
No edit summary |
No edit summary |
||
Line 1:
:''For the material and its properties and uses, please see [[porcelain]].''
This article is concerned with the '''porcelain''' wares of China, from early times until the present day. In scope it covers a wide range of Chinese high-fired ceramics, some of which would probably not be recognised as ''porcelain'' under some Western definitions of that term.
== Materials ==
Chinese porcelain is mainly made using [[porcelain stone]], [[china clay]] or a combination of the two materials. Both minerals derive from the weathering and decomposition of [[granitic]] [[rock (geology)|rock]]s. China clay largely comprises the clay mineral [[kaolinite]] ''(Gaoling)''. Porcelain stone, [[petunse]] ''(baidunzi)'', is a [[micaceous]] rock of variable composition which includes [[quartz]] and [[sericite]] (Kerr and Wood 2004), although porcelain stone can also occur kaolinised to a greater or lesser extent.
A commonly-held but erroneous belief that Chinese porcelain stone is [[feldspar|feldspathic]] in character was disproved early in the twentieth century (Kerr and Wood 2004). Porcelain stone and china clay are both ''platy'' minerals, which is to say that they are composed to varying degrees of small platelets of high surface area (external and internal) and are capable of holding relatively large amounts of [[water]]. This is of importance because most of the methods used for forming the body parts of ceramic pieces (''throwing'' on a wheel, for example) depend upon the application of [[compression]] to align the platelets and increase the [[plasticity]] and workability of the clay mixture. In the case of throwing, compression is applied by the hand of the potter.
== Classification ==
In the Western tradition ceramics are primarily divided into the categories of [[earthenware]], [[stoneware]] or [[porcelain]], depending upon the composition of the body material and the temperature at which the ware matures into a stable [[crystaline]] matrix. The Chinese tradition recognises only two primary categories of ceramic, high-fired [cí 瓷] and low-fired [táo 匋]. This can lead to confusion because, for example, in China no distinction is drawn between high-fired stonewares and porcelain (Pierson 1996). One result of this is that the property of [[resonance]] carries greater weight than that of [[translucence]] in the Chinese classification of high-fired ceramic wares.
Chinese porcelain is usually ''green-fired'' or ''once-fired'', which means that the body and the glaze are fired together. After the body of a piece is formed and finished it is air-dried, coated with a glaze, dried again and fired. In the high temperature of the [[kiln]] the body and the glaze are fused together to become a unit. Chinese [[enamel]]led wares are also produced in this way, but the enamels are added after the first, high-temperature, firing and the pieces are sent for a second firing in a smaller, lower-temperature kiln.
== History ==
In the context of Chinese ceramics the term ''porcelain'' lacks a universally accepted definition. This in turn has led to confusion about when the first Chinese porcelain was made. Claims have been made for the late [[Eastern Han Dynasty|Eastern Han]] period (100 to 200 AD) the [[Three Kingdoms]] period (220 to 280 AD) the [[Six Dynasties]] period (220 to 589 AD) and the [[Tang Dynasty]] (618 to 906 AD).
A body of Chinese scholarly opinion is currently of the view that the first true porcelain was made in the Chinese province of [[Zhejiang]] during the Eastern Han period, but this opinion is controversial. However, Chinese experts emphasise the presence of a significant proportion of porcelain-building minerals (china clay, porcelain stone or a combination of both) as an important factor in defining ''porcelain'' and shards recovered from Eastern Han kiln sites in [[Zhejiang]], estimated to have been fired at a temperature of between 1260 to 1300 degrees Celsius, were found that met this condition (He Li 1996).
During the [[Sui Dynasty|Sui]] and [[Tang Dynasty|Tang]] periods (581 to 906) a wide range of ceramics, low-fired and high-fired, were produced. These included the well-known Tang lead-glazed ''sancai'' (three-colour) wares, the high-firing, lime-glazed ''Yue'' celadon wares and low-fired wares from ''Changsha''. In northern China, high-fired, translucent porcelains were made at kilns in the provinces of [[Henan]] and [[Hebei]].
==Mixing porcelain stone and china clay==
During the [[Song Dynasty|Song]] and [[Yuan Dynasty|Yuan]] dynasties porcelain was made at [[Jingdezhen]] and other kiln sites in southern China using crushed and refined porcelain stone alone, but by the early eighteenth century china clay and porcelain stone were mixed in about equal proportions. China clay when added to the body material produced a porcelain of great strength and whiteness (whiteness, in particular, was a much sought after property of porcelain, especially that used for blue and white wares).
Porcelain bodies made from porcelain stone fire at a lower temperature, in the region of 1200 degrees Celsius, than those made with a mixture of china clay and porcelain stone, which require firing in the region of 1350 degrees Celsius.
The temperatures within a typical large, southern egg-shaped kiln varied greatly, from hot, near the firebox, to cooler, near to the chimney at the opposite end of the kiln. One advantage gained by the addition in varying amounts of china clay was that the composition of the mix could be varied to suit the position that the wares made from it would occupy in the kiln, with a clay-rich mix being used for wares to be fired at the hot end of the kiln and a stone-rich mix being used for wares to be fired at the cooler end of the kiln.
== North and south ==
Chinese ceramic wares are often classified as being either ''northern'' or ''southern'', called so because present day China comprises two separate, and from the geological point of view distinctly different [[land mass]]es by the same name. The two land masses were brought together by the action of [[continental drift]], forming a junction that lies between the [[Yellow river]] and the [[Yangtze river]]. Geological differences between the northern and the southern land masses have influenced the nature of the [[ceramics|ceramic wares]] made in the two areas and, for example, in the north ceramic wares tend to have bodies made using mainly china clay, in the south ceramic wares tend to have bodies made using mainly porcelain stone. In turn, this led to the development of coal-fuelled kilns suitable for the slow, high-temperature firing of clay-rich wares in the north and wood-fuelled kilns more suitable for the faster, lower-temperature firing of the stone-rich southern wares.
== Jingdezhen ==
[[Image:Porcelain Workshop, Jingdezhen, Jiangxi, China.jpg|thumb|Porcelain workshop in Jingdezhen]]
The city of [[Jingdezhen]] has been an important centre for the production of ceramics in southern China since at least the early [[Han Dynasty|Han]] Dynasty. The early wares were low-fired but by the time of the [[Southern and Northern Dynasties]] (420 to 589) locally available raw materials were being used to produce a form of porcelain. In the year 1004, under the Song emperor [[Jingde]], the newly re-named city of Jingdezhen was established as a centre for the production of [[Imperial porcelain]].
Detailed descriptions of the manufacture of porcelain at Jingdezhen during the [[Qing Dynasty|Qing dynasty]] exist, including a memoir written by Tang Ying and the letters of [[Père d'Entrecolles]].
Two letters written by Père Francois Xavier d'Entrecolles {{ref|letters}}, a [[Jesuit]] missionary (and industrial spy) who lived and worked in Jingdezhen, described in detail the methods and materials used in the manufacturing process of porcelain wares in the later years of the reign of the [[Kangxi]] emperor; an important period in the history of Chinese ceramics. In his first letter, dated 1712, d'Entrecolles described the way in which porcelain stone was crushed, refined and formed into little white bricks known in Chinese as ''petuntse'' or ''baidunzi''. He then went on to describe the refining of china clay, ''kaolin'' or ''Gaoling'', the preparation of glazes, the stages of forming porcelain wares, glazing and firing. Père d'Entrecolles, explaining his motives for describing what he had seen at Jingdezhen, states that ''"Nothing but my curiosity could ever have prompted me to such researches, but it appears to me that a minute description of all that concerns this kind of work might, somehow, be useful in Europe"'' but his first letter came too late to be of much help in the European search for the secret of making porcelain. In 1743, during the reign of the [[Qianlong]] emperor, Tang Ying, the imperial supervisor at Jingdezhen produced a memoir entitled ''"Twenty illustrations of the manufacture of porcelain."'' Unfortunately, the original illustrations have been lost but the text of the memoir is still accessible, together with photographs replacing the missing illustrations and an additional commentary. {{ref|memoir}}
== Some notable Chinese porcelain wares ==
=== Jian tea wares ===
[[Image:jian_bowl.jpg|thumb|right|150px|Song dynasty Jian tea bowl (Metropolitan Museum of Art).]]
Jian blackwares, mainly comprising tea wares, were made at kilns in the county of Jianyang in the province of [[Fujian]] and reached the height of their popularity during the Song dynasty. The wares were made using locally-won, iron-rich clays and fired in an oxidising atmosphere at temperatures in the region of 1300 degrees Celsius. The glaze was made using clay similar to that used for forming the body, but fluxed with wood-ash. At high temperatures in the kiln phases within the molten glaze separated to produce the patterning called ''hare's fur''. Some pooling of the glaze is usually evident in Jian wares and where the bowls were set tilted for firing the glaze often ran into drips on one side of the bowl.
The ''hare's fur'' Jian tea bowl illustrated is in the Metropolitan Museum of Art in New York. It was made during the Song dynasty (960 to 1279 AD) and exhibits the typical pooling, or thickening, of the glaze near to its foot. The ''hare's fur'' patterning in the glaze of this bowl resulted from the random effect of phase separation during early cooling in the kiln and is unique to this bowl, no two bowls have identical patterning. The bowl also has an ''iron-foot'' which is typical of these wares. It would have been fired, probably with several thousand other other pieces, each in its own stackable saggar, in a single-firing in a large dragon kiln. One such kiln, built on the side of a steep hill, was almost 150 metres in length, though most Jian dragon kilns were fewer than 100 metres in length.
Jian tea wares of the Song dynasty were greatly appreciated and copied in Japan, where they were known as ''temmoku'' or ''tenmoku'' wares. Phase separation in the iron-rich glazes of Chinese blackwares was also used to produce the well-known ''oil-spot'', ''teadust'' and ''partridge-feather'' glaze effects.
=== Qingbai wares ===
Qingbai wares were made at Jingdezhen and at many other southern kilns from the time of the [[Northern Song Dynasty]] until their almost complete eclipse, starting early in the fourteenth century, by underglaze-decorated blue and white wares. The qingbai glaze is a ''porcelain glaze'', so-called because it was made using porcelain stone. The qingbai glaze is clear, but contains [[iron]] in small amounts. When applied over a white porcelain body the glaze produces a greenish-blue colour that gives the glaze its name (''qingbai'' in Chinese means ''greenish-blue''). Bowls, some with incised or moulded decoration and varying from the everyday to more finely made pieces represent the overwhelming bulk of surviving qingbai wares.
[[Image:Qingbai.JPG|thumb|right|150px|Song dynasty ''qingbai'' bowl]]
The Song dynasty qingbai bowl illustrated was possibly made at the Jingdezhen village of [[Hutian]], which was also the site of the Imperial kilns established in the year 1004. The bowl has incised decoration, probably representing clouds or the reflection of clouds in the water. The body is white, translucent and has the texture of very fine sugar, indicating that it was made using crushed and refined porcelain stone, rather than a mixture of porcelain stone and china clay. The glaze and the body of the bowl would have been fired together, in a [[Saggar fired pottery|saggar]], in a large wood-burning ''dragon-kiln'' or ''climbing-kiln'' typical of southern kilns of the period.
Though not the case with the bowl illustrated, many Song and Yuan qingbai bowls were fired upside down in special segmented saggars, a technique first developed at the [[Ding Ware|Ding]] kilns in [[Hebei]] province. The rims of such wares were left unglazed but were often bound with bands of [[silver]], [[copper]] or [[lead]].
=== Blue and white wares ===
[[Image:bluepot.JPG|thumb|right|150px|Kangxi period (1662 to 1722) blue and white porcelain tea caddy]]
Following in the tradition of earlier ''qingbai'' porcelains, blue and white wares are glazed using a transparent ''porcelain glaze''. The blue decoration is painted onto the body of the porcelain before glazing, using very finely ground [[cobalt oxide]] mixed with water. After the decoration has been applied the pieces are glazed and fired.
It is believed that underglaze blue and white porcelain was first made in the Tang Dynasty. No complete piece of Tang blue and white is known to exist, but shards dating to the eighth or ninth century have been unearthed at [[Yangzhou]] in the [[Jiangsu|Jiangsu province]]. It has been suggested that the shards originated from a kiln in the province of [[Henan]]. In 1957 excavations at the site of a [[pagoda]] in the province [[Zhejiang]] uncovered a Northern Song bowl decorated with underglaze blue and further fragments have since been discovered at the same site. In 1970 a small fragment of a blue and white bowl, again dated to the eleventh century, was also excavated in the province of Zhejiang. In 1975 shards decorated with underglaze blue were excavated at a kiln site in [[Jiangxi]] and, in the same year, an underglaze blue and white [[urn]] was excavated from a tomb dated to the year 1319, in the province of [[Jiangsu]]. It is of interest to note that a Yuan funerary urn decorated with underglaze blue and underglaze red and dated 1338 is still in the Chinese taste, even though by this time the large-scale production of blue and white porcelain in the [[Yuan Dynasty|Yuan]], [[Mongol]] taste had started at Jingdezhen.
Starting early in the fourteenth century, blue and white porcelain rapidly became the main product of Jingdezhen, reaching the height of its technical excellence during the later years of the reign of the [[Kangxi]] emperor (du Boulay 1973) and continuing in present times to be an important product of the city.
The [[tea caddy]] illustrated shows many of the characteristics of blue and white porcelain produced during the Kangxi period. The translucent body showing through the clear glaze is of great whiteness and the cobalt decoration, applied in many layers, has a fine blue hue. The decoration, a sage in a landscape of lakes and mountains with ''blazed'' rocks is typical of the period. The potting is well executed and the porcelain body is finely textured, indicating the presence of a significant proportion of china clay in the paste. The piece would have been fired in a [[Saggar fired pottery|saggar]] (a lidded ceramic box intended to protect the piece from kiln debris, smoke and cinders during firing) in a [[reducing atmosphere]] in a wood-burning ''egg-shaped'' kiln, at a temperature approaching 1350 degrees Celsius.
== Fakes and reproductions ==
Chinese potters have a long tradition of borrowing design and decorative features from earlier wares. Whilst ceramics with features thus borrowed might sometimes pose problems of provenance, they would not generally be regarded as either reproductions or fakes. However, fakes and reproductions have also been made at many times during the long history of Chinese ceramics and continue to be made today in ever-increasing numbers.
* Reproductions of Song dynasty [[Longquan celadon]] wares were made at Jingdezhen in the early eighteenth century, but outright fakes were also made there, using special clay and artificially aged by boiling in meat [[broth]], refiring and storage in [[sewer]]s. Père d'Entrecolles records that by this means the wares could be passed off as being hundreds of years old.
* At Jingdezhen the two remaining wood fired, egg-shaped kilns produce convincing reproductions of earlier wares and at Zhejiang province good reproductions of Song Longquan celedon wares continue to be made in large, side-stoked dragon kilns.
* Before [[World War II]], the English potter [[Bernard Leach]] found what he took to be genuine Song dynasty ''cizhou'' rice-bowls being sold for very little money on the dock of a Chinese port and was surprised to learn that they were in fact newly made.
* In modern times the market for Song dynasty ''Jian'' tea-bowls has been severely depressed by the appearance in large numbers of modern fakes good enough to deceive even expert collectors. It is reported that some of these fakes show evidence of having had genuine Song dynasty ''iron-foot'' bases grafted onto newly made bodies.<!--source?-->
* In the late nineteenth century fakes of Kangxi period ''famille noire'' wares were made that were convincing enough to deceive the experts of the day. Many such pieces may still be seen in museums today, as may pieces of genuine Kangxi porcelain decorated in the late nineteenth century with ''famille noire'' enamels. A body of modern expert opinion holds that porcelain decorated with ''famille noire'' enamels was not made at all during the Kangxi period, though this view is disputed (de Boulay 1973).
[[Image:Kangxi_mark.jpg|thumb|right|150px|Kangxi reign mark on a piece of late nineteenth century blue and white porcelain.]]
* A fashion for Kangxi period (1662 to 1722) blue and white wares grew to large proportions in Europe during the later years of the nineteenth century and triggered the production at Jingdezhen of large quantities of porcelain wares that looked back to the ceramics of the earlier period. Such blue and white wares were not fakes or even convincing reproductions, even though some pieces carried four-character Kangxi reign-marks that continue to cause confusion to this day. Kangxi reign-marks in the form shown in the illustration occur only on wares made towards the end of the nineteenth century or later, without exception.<!-- who is to say modern day fakes can't have a fake mark? Note: "or later". -->
===Authentication===
The value of ''testing'' in the authentication of Chinese porcelain is disputed. The most widely-known test, the [[thermoluminescence]] test (TL-test) can be used to provide an estimate, within very wide limits, of the date of last firing. The test is carried out on small samples of porcelain drilled or cut from the body of a piece, which can be risky and disfiguring. For this reason the test is rarely used for dating finely-potted, high-fired ceramics. Other tests can be used to determine the composition of glazes and body materials, for comparison with the results of analyses carried out on reference specimens of known [[provenance]]. It is however widely held <!-- by who?--> that at best, testing can only be of use when combined with other, more traditional, methods for helping to establish provenance. Such methods might including comparative techniques, expert opinion <!-- expert opinion isn't a technique--> and the evaluation of written and verbal records, where these are available.
==Notes==
#{{note|letters}}[http://www.ceramicstoday.com/articles/entrecolles.htm Two letters written by Père Francois Xavier d'Entrecolles] at Ceramics Today.com
#{{note|memoir}} [http://www.seattleartmuseum.org/Exhibit/Archive/porcelainstories/process/process.htm Tang Ying's "Twenty illustrations of the manufacture of porcelain."] at the [[Seattle Art Museum]].
== References ==
* de Boulay, Anthony (1973). ''Chinese Porcelain''. Octopus Books, London. ISBN: 0 7064 0045 3.
* He Li, (1996). ''Chinese Ceramics. The New Standard Guide''. Thames and Hudson, London. ISBN: 0 500 23727 1.
* Kerr, Rose and Wood, Nigel (2004). ''Science and Civilisation in China,'' Volume 5, Part XII: Ceramic Technology. Cambridge University Press. ISBN: 0 521 83833 9.
* Kotz, Suzanne (ed.) (1989) ''Imperial Taste. Chinese Ceramics from the Percival David Foundation.'' Chronicle Books, San Francisco. ISBN: 087701 612 7.
* Pierson, Stacey, (1996). ''Earth, Fire and Water: Chinese Ceramic Technology.'' Percival David Foundation of Chinese Art, University of London. ISBN: 07286 0265 2.
=== See also ===
* [[Blanc-de-Chine]] (the white wares of Dehua).
* [[Canton porcelain]] (Jingdezhen porcelain decorated at Canton for export to the West).
* [[Chinese export porcelain]] (Chinese porcelain made for export to the West).
* [[Dehua porcelain factories]] (the factories at Dehua).
* [[Famille jaune, noire, rose, verte]] (enamelled wares of the eighteenth and nineteenth centuries).
* [[Kraak porcelain]] (blue and white export wares in the Dutch taste).
* [[Longquan Celadon]] (the celadon wares of Longquan county).
* [[Swatow ware]] (wares exported through the port of Swatow).
* [[Tangshan]], [[Hebei]] province (the ''porcelain capital'' of northern China).
* [[Yixing clay]] (the red stonewares of Yixing).
[[Category:Chinese porcelain|*]]
| |||