When buying blue-and-white porcelain, you must pay attention to this kind of spots, do not miss!
Recently, a tea friend to little understand sent some photos, said that he bought a firewood kiln of blue and white porcelain master cup, beautiful is not like the power of the school ~ ~
As he watched and played with delight, he suddenly found that the scales were missing, and that there was a bulge of silver!
So this tea friend is anxious to ask: Is this cup defective?This isn’t a flaw?
Small understand to consult relevant industry experts, expert appraisal, gave the answer:
This is a “flaw”.
It is a flaw that cannot be sought.
For example, it’s like a “one”beauty nevus(Please ignore the position of “beauty mole”).
. ..this somewhat hollow scar, known by its scientific name.tin spotThere are many kinds of blue and white flowers.
Say it is tin spot, in fact, is not tin, but iron oxide, because the color similar to tin silver-gray reflection, so called tin spot.
The place that has tin spot, feel can have convex and concave feeling, line inside commonly call “eat a tire”.
Some of the serious shrinkage along the surface of tin spots will even appear in the phenomenon of tire.
As for the tin patch, Mr. Geng Baochang has an intuitive and incisive definition in his book “The Identification of Porcelain in Ming and Qing Dynasties”:
“Often in the grain of a linecrystal spot of cobalt and iron, a star-shaped spot is scattered, there are fewer crystalline spots in the shallow, dense areas are condensed into black-blue, dark-blue or metal-tinted, and concave deep into the fetal bones,To look sideways in the light or to touch with your hand to discern an uneven shape.”
So, how did the tin patch come from?
There are two reasons
The first is that the local iron in the green material is too high, in the high-temperature glaze in the state of saturation, after the heating of the kiln, the temperature drops, the saturated part of theIron begins to precipitateIt is easy to produce tin spots on the objects;
The second is, when the painter draws, inTo write, dang, or stack a pen.collection of local and green materialsAfter the high temperature, will form irregular black condensation spots, thick areas will often form tin spots.
The formation of tin spot, although there are human factors, but also the providence for it.
However, some of the tin spots have no metallic luster,
Why is that?
Because this black spot is not a real tin spot, but ratherblack coacervate spotIt’s not the same thing as tin spots.
In “the Yuan Dynasty Qinghua and multicolored porcelain” in the book said:
“Imported green material for high-iron low manganese, fired out of the blue flowers, on the color is rich, black spots, in the black dense place flashing such as lead, commonly known as’ tin ‘or’ iron rust spots’.”
That is to say, blue flowers in high temperature firing will first have black condensation spots, and black condensation spots in different angles can reflect the white tin light “rust mark” part, can be called “tin spot”.
So, why does tin spot feel concave-convex?
This has to do with the cause of the green material itself and the firing process.
Glazed surface depression is mainly in the firing, high iron content of the green material will produce condensation spots, agglomerating spots on the ceramic tire and glaze has a strong infiltration, mutual integration, in the condensation spot most places, will penetrate downward into the ceramic tire, cause glaze depression,It’s also called eating a baby.
The phenomenon of bulge is caused by the combination of large particles in the green material and iron and glaze in the firing process.
As we mentioned above, the coacervate spots have strong permeability to both the ceramic tire and the glaze.
Not only can it penetrate into the porcelain tyre, but it can also be combined with the glaze upward, and with the continuous analysis of the iron element in the process of floating encountered in the green material of large particles, the tin spot will form a small protuberance.
There have also been changes in the aesthetics of tin patches.
Like the plump beauty of the Tang Dynasty, it is now fashionable to have a cold face, and the tin patch has gone throughreduce to being raisedThe process of.
During the period from the late Yuan Dynasty to the early Ming Dynasty, what the royal official kiln used was imported from abroad. Although the price of the green material was comparable to gold, it was often disliked by the literati at that time because of the tin specks.
By the middle and late Ming Dynasty, people’s aesthetic began to change.
Like Venus, with her broken arm, the blue and blue flowers with tin patches are loved by more and more people, even by othersblue and white top quality.
In short, tin spot is not often, is the green material, glaze, painting, burning and other elements of the formation of a comprehensive and accidental, with a word that is” article this day into the day, a wonderful hand, “is a chance coincidence will only appear under the phenomenon.