· View on fragmentary ceramics
· The small plate makes my dream come true
· "Oriental Titanic" 's emergence from the sea


Distinguishing ancient ceramics by checking blebs

  No matter ancient or modern ceramics, there are always some small blebs hidden under the glaze which thickly bestrew the glaze. However, the numbers of the blebs are not always the same. Why does this happen? Can we distinguish ancient ceramics and modern ceramics by studying the shape and distribution of the blebs? By holding such point of view, I find another way to identify the ceramics which is bleb appraisal.

Cause of formation for blebs

  The blebs came from water molecules in the glaze. While being fired, the crystal water and water in liquid state turn into gas gradually because of the high temperature. If the glaze is thick, the water in gas state will be encased by the surface and cannot release so that the blebs come into being. On the contrary, the blebs will break out from the glaze surface so that concave forms. The more the water molecules are, the more the blebs. If there is no water molecule in the glaze, there will be no bleb under the glaze.
The blebs are different according to different technique used in producing glaze in each dynasty which provides advantageous condition for ceramic appreciating.

Classification and technical characteristics of glaze

  To some degree, the productive standard of ceramics depends on the technique in producing glaze. There has been a long history for producing ceramics in China where the technique was mature in ancient times.
  According to the firing temperature and fused capacity, the glaze can be classified as soft glaze, enamel glaze and hard glaze. According to the way of producing, it can be classified as raw glaze, frit glaze and volatile glaze.
  Based on the way of coating glaze, it can be classified as dunking, pouring, spraying, dripping, brushing, volatilizing and so on. Different ways are used in different time according to the batch formula of the glaze.
  With the improvement of techniques, the blebs under the glaze changed accordingly, especially in strypped-down technology. All these traits in producing glaze manifest a new stage in the appreciation of ancient ceramics.

The appraisal of ancient ceramics in Song and Yuan dynasty

  In the history of Chinese ceramics production, it is Song dynasty that occupy one of the flourishing periods. At that time, the kilns mainly located in the provinces of Henan, Hebei, Shanxi, Shanxi, Shandong and so on. Among all the kilns, Ru, Guan, Ge, Jun, and Ding kiln belonged to five top ones and followed by Longquan, Yaozhou, Cizhou, Dengfeng kilns, etc. They are beautiful in glaze, elegant in shape and most of them are made for emperors. So they are hard to be imitated by others because of the difficult technology.
  I thoroughly tested the ceramics fired in Ru, Guan, Ge, Jun, Ding kilns and found that they have the same trait, that is, there is little or even no bleb under the glaze which just suit that of the ceramics in Song dynasty.
  In general, the ceramics should be appraised from different aspects, including the color of the glaze, the blebs, the flecks and so on.
  What is more, there is no bleb in all the mimics and the ceramics produced after Yuan dynasty. So it is not ceramics of Song dynasty if blebs can be seen under the glaze, such as Lujun glaze of Yongzheng period, Guangjun of Ming dynasty and Fangjun.

  It is the same as blue and white produced in Yuan dynasty which is hard to be seen and difficult to be distinguished. You can only differentiate them from the blebs.
  In the blue and white glazed ceramics, the white blebs occupy a large proportion. If the blue and white glaze is thin, a great deal of concave can be found by being magnified 50 times.

The discrimination of blue and white and underglaze red in Ming and Qing dynasty

  Although the appraisal of blebs is very important, ceramics should be distinguished from different aspects. There are many blue and white and underglaze red ceramics produced in these two periods and so are the mimics. The most difficult part in the imitation is about the blebs.
  Following such rules, you can distinguish the facticity of the ceramics effectively. The blue and white glaze is the first target of your examination. If there is no white bleb on the glaze but only concaves can bes found, or the glaze is thin and the blebs are small, then such kind of ceramics must be fake ones. On the contrary, if the blebs are numerous and big, they must be real.




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