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.
of formation for blebs
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.
and technical characteristics of glaze
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
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.
appraisal of ancient ceramics in Song and Yuan dynasty
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.
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
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.
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.
discrimination of blue and white and underglaze red in Ming and
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.
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.