My system is not decent

Over the past dynasties, there have been many changes in porcelain, especially the glaze and glaze color.

The enamel of the Jun kiln in the Song Dynasty is as thick as grease; the enamel of the Ding kiln is mostly tear-stained;

The surface and interior glazes of Yuan Dynasty cutters were often inconsistent, and there were often defects such as kiln cracks, glaze leakage, glaze shrinkage, and flattening;

The mouth, bottom, corners and the thin part of the glaze of Yongle white-glazed utensils are mostly white and yellowish, while the places where the glaze is thick and thick have a light pea-green color.

The red glaze of Kangxi Lang Kiln has the characteristics of the so-called "off-mouth, hanging feet and no flow" and "rice soup base".

The various characteristics of porcelain in the past dynasties are all unique technical manifestations, and many of them are difficult to imitate in later generations.

The porcelain in front of me is obviously in line with the characteristics of the Ru kiln in the Northern Song Dynasty, but when identifying the glaze, we must also pay attention to the size and density of the air bubbles contained in the glaze.

The glazes of Guan and Ge kilns are as dense as pearls, while the glazes of Ru kilns are as sparse as morning stars, and the glazes of Xuande have "brown eyes".

The celadon glazes handed down from the official kilns, Ge kilns and Ru kilns of the Song Dynasty have dense network-like patterns.

The reason for its formation is mainly due to the inconsistent expansion coefficients between the glazes.

That is, after the porcelain is fired, the shrinkage is not synchronized after gradually cooling down and exiting the kiln.

The thick or thin, long or short cracks that appear on the glaze of the one-color glazed porcelain are intentionally made by the kiln workers for beautification.

Glaze with flakes, a special recipe.

Only by figuring out this formula can the opening on the porcelain show the effect the author wants.

Looking at the very natural porcelain in front of him, with tight openings, Chen Wenzhe studied it bit by bit.

Appraisal means not to miss any detail.

No matter how good your imitation is in other places, as long as there is one mistake, all the advantages can be overturned.

The glaze layer is like curd fat, and the internal air bubbles are like morning stars. All these characteristics match Ru kiln porcelain!

Not finding any flaws made Chen Wenzhe both happy and worried.

Happily, he might be able to get a piece of Ru Kiln porcelain from the Northern Song Dynasty.

What is worrying is that maybe his technology is outdated, and he can't confirm the authenticity of this porcelain!

"We still have to watch the movie!" Chen Wenzhe re-confirmed his thoughts on the appraisal as his thoughts turned quickly.

Even though he really wanted to see what the glaze formula used for this piece of porcelain looked like, he still held back.

Porcelain in hand, it can't run away, as long as we study the opening technology of this piece of porcelain carefully, and confirm that the opening technology of this piece of porcelain can reach the realm of Ru kiln porcelain in the Northern Song Dynasty, then it will be fine.

If it is really good, this technique of opening film can be of great help to him in imitating Ru kiln porcelain.

At that time, the authenticity of this porcelain will not matter.

Therefore, the most important thing is to slice porcelain, which is also the most difficult technique for Chen Wenzhe to master.

This is a three-legged brush washer with celadon glaze from a Song Ru kiln. It looks a bit like a three-legged bottle holder, because it is very similar to a brush washer.

It is 4cm high, with a diameter of 18.5cm and a foot distance of 16.9cm.

The bearing plate has a round mouth, a shallow belly, a flat bottom, and three legs underneath.

The inside and outside are covered with azure glaze, and the glaze surface is covered with fine grains.

The outsole is fully glazed, with 5 small burnt nail marks.

谷贌

Although the shape of the utensil is relatively simple, the shape is regular, and the glaze is light sky blue, soft and moist.

The overall shape of the vessel is fine, so to identify such a piece of porcelain, you still need to look at other features, such as the most important piece, if there is a problem with the piece, then you don’t need to look at other places.

After careful inspection, Chen Wenzhe found that the opening technique of this piece of porcelain is really special.

It is cracks from the glaze layer to the carcass.

This kind of deep opening, called "Guogang", is naturally formed during the kiln firing process in the kiln.

The shallow cracks are caused by the continued shrinkage of the glaze after leaving the kiln.

Due to the different sizes and depths of the slices, the exposed parts of the carcass are also oxidized or polluted.

Therefore, the large opening is dark gray like iron, so it is called iron wire;

The small openings are yellowish brown like gold, so they are called gold wire.

"Golden thread and iron thread" refers to these two conditions, and it is most prominently displayed on Ge kiln wares, and has formed a distinctive feature of the times.

The pattern on the official kiln wares is different from that on the Ge kiln wares. The patterns are all deep-seated "Guogang" and the pattern is relatively large. Its shape is like the ice layer that suddenly cracked on the ice surface of a river in winter. , layer upon layer of exquisite incomparable.

The split pattern on the glaze of Ru porcelain is finely divided and dense, commonly known as "crab claw pattern".

It is a classic piece, no problem at all. Seeing the opening of this piece of porcelain, Chen Wenzhe even felt a little bit learned.

At this time, he had already begun to be a little serious. Perhaps this piece was really Ru Kiln porcelain from the Northern Song Dynasty.

Instead of caring about authenticity, Chen Wenzhe began to look at craftsmanship.

So what if it's true or false?Only if the workmanship is good enough can it be of sufficient value to him.

For example, the glazed surface, after being glazed, fired, and finally the glazed surface gives people a good enough look and feel, a piece of porcelain is valuable.

The appearance of glaze includes two aspects of texture and color.

The texture of glaze generally refers to the degree of moistness of the glaze surface, and the thicker the glaze layer, the more moist it is.

The thickness of the glaze on this piece of porcelain in front of me is obviously high, so this is not the kind of thin glaze on the celadon of the Northern Song Dynasty.

In general, most of the porcelains that have this situation are official kilns in the Southern Song Dynasty.

Of course, Southern Song official kiln porcelain also has two types of glaze, thick glaze and thin glaze, and the glaze surface of thick glaze is the most moist.

Thick-glazed Southern Song official kiln porcelain needs to be glazed two or three times or even four or five times. After the first few times of glazing, the glaze must be fired at a low temperature of about 800c, which is called plain firing, and the last time is fired at a high temperature of 1230-1270c. Made of porcelain.

In the excavation of the kiln site of modern Southern Song official kilns, low-temperature biscuit furnaces and waste products that were not glazed after low-temperature firing were found.

The purpose of multiple glazes is to make the glaze have a warm and moist texture like jade, and to cover the dark gray body color.

In some Southern Song Dynasty official kiln porcelains, the color of the fetus is dark gray due to the mixture of purple gold soil.

From the perspective of silicate, celadon porcelain has three kinds of glazes: plant gray glaze, lime glaze and lime alkali glaze.

The glaze on the original celadon is grass gray glaze, which is characterized by uneven glaze layer. The celadon glaze from the Eastern Han Dynasty to the Northern Song Dynasty is lime glaze. The glaze is more uniform than the original celadon, but the texture of jade is not strong.

The official kilns of the Southern Song Dynasty began to have lime-alkali glaze, and its enamel was as moist as jade.

The main components of the glaze are porcelain stones, slurry water and glaze ash.

The flux (calcium oxide) in celadon glaze is mainly provided by glaze ash. If the amount of glaze ash is reduced during glaze preparation, the content of calcium oxide in the glaze will decrease, and the proportion of potassium oxide and sodium oxide will increase relatively. Potassium and sodium are alkali metal elements, so the glaze with this composition is called lime-alkali glaze.

The reduction of calcium element will relatively reduce the amount of flux. During the firing process, the glaze will not flow obviously due to sufficient melting, and will pile up on the ring feet. Moreover, the glaze fired in this way has a warm and moist texture. Jade.