Of course, in addition to the above processes, there are other processes.
For example, a layer of white glaze is first applied on the object as the ground glaze, and a thin layer of green glaze containing copper oxide is applied on the white glaze, and then fired at high temperature in an oxidizing atmosphere.
This kind of green glaze utensils were not well known by people in the past.
In previous archaeological excavations, many kilns in the northern region have discovered so-called "white glaze and green color" artifacts from the late Tang to the Northern Song Dynasty.
From this we can actually see that the porcelain of the Song Dynasty played a role as a link between the past and the following.
There were not many colored glazed porcelains in the Song Dynasty, and they were generally single-color glazes, such as celadon and white porcelain.
At most, there are some green glaze, black glaze, and sauce glaze porcelain.
At this time, Chen Wenzhe suddenly realized that when he was making green glazed porcelain in South Vietnam, there seemed to be no finishing touches.
For example, it seems that he did not make the white-glazed green-colored porcelain of the Northern Song Dynasty.
In other words, when he got here, he was distracted, attracted by other porcelain, and turned to other porcelain.
Now that he had nothing to do, he naturally wanted to find something to do.
Therefore, he started with low-temperature glaze. If possible, he wanted to re-fire all the five famous kilns of the Song Dynasty.
It is not easy to re-fire the five famous kilns, but it is not difficult to start with low-temperature glaze and fire some green glaze porcelain first.
The production method of so-called "white glaze green color" utensils is consistent with the above-mentioned process flow.
It's just that the green color on most utensils is only used as a decoration on a small area in local areas.
For example, during the excavation of the Cizhou Kiln site, the white-glazed green-colored incense burners, bottles, jars and other utensils unearthed from the earliest strata were only decorated with some green spots along the edges and belly of the utensils.
However, more white-glazed green-colored porcelain was found in the early strata of the Yaozhou kiln in Tongchuan, Western Shaanxi, and in the Husha kiln.
Moreover, the green spots decorated on some utensils are very large, covering most of the surface of the utensils. These utensils are fired at high temperatures in one go.
It can be seen that there is basically no problem in the process of applying green color on white glaze and firing it once.
As for the firing temperature, and whether it is lower than that of ordinary white glazed porcelain, it is still unknown because there is no good test data.
The best example is the porcelain from the Tang Dynasty shipwreck of the Black Stone that was salvaged in Belitung Island off the coast of Indonesia in recent years.
Porcelain bearing the date of the second year of Baoli (826) in the Tang Dynasty was discovered from this sunken ship.
The ship sank probably not much later than this era.
More than 60,000 pieces of porcelain were released from the Black Stone, including hundreds of white-glazed green-colored porcelain produced in the northern region.
These porcelains often have large areas of green spots, which are scattered and flowing, covering most of the surface.
When the green glaze on the surface of the vessel is sufficient, green covers the entire surface of the vessel, and it becomes green-glazed porcelain.
A piece of green-glazed bottle in Wanwan's private collection is considered to be a product of Nanhe Gongyi Kiln. The upper part can be called a green-glazed vessel, but the application method of green color spots can also be seen on the abdomen.
This object is a good example of dense green stains turning into green glaze.
The characteristic of this type of green glaze artifact is that the green color is relatively light and bright.
Among several kinds of green glaze utensils, the color is the clearest and brightest.
However, the green color is obviously mottled and uneven, and generally has a thinner character.
At present, this type of green glaze artifacts are mainly found in the late Tang Dynasty, but also in Cizhou Kiln and some kilns in the central and western regions of Nanhe.
For example, white-glazed green-colored porcelain produced by Xinmi Xiguan Kiln, Hebi Ji Kiln, etc. was very popular in the early Northern Song Dynasty and continued to be produced until the late Northern Song Dynasty.
Therefore, it should be reasonable for the late Northern Song Dynasty to adopt this method to produce green glaze wares.
In 2005, the Shendu Municipal Cultural Relics Research Institute once again excavated the Longquanwu kiln site of the Liao Dynasty in MTG District on a large scale.
Among the unearthed objects from the strata of the late Liao Dynasty, green-glazed porcelain pieces that were glazed in the same way as this green-glazed plum vase were discovered.
This is a good example that this kind of green glazed porcelain continued to be produced into the late Northern Song Dynasty.
In the past, it was not known whether the Ding kiln produced this type of green-glazed porcelain. Later, a plum vase was found, which has reliable test data, and can be used as evidence that the Ding kiln produced this type of green-glazed porcelain.
The coloring agent of green glaze is copper oxide, and lead compound is used as the basic co-solvent. It is a low-temperature lead glaze that is put into the kiln twice (800-1000°C).
Generally, the plain body is fired first, and then the glaze is applied and baked at low temperature.
Green glaze products fired in Ding kiln have been produced in large quantities from the middle and late Tang Dynasty to the late Jin Dynasty, and the types of green glaze are very rich.
The firing of green glaze may have evolved from the inheritance of Tang Sancai technology.
The Dingzhou Museum now has a complete Ding kiln green glaze carved pillow from the Jin Dynasty that belongs to the Cizhou kiln style. The pillow has a thick body, gray-black color, and a typical Ding kiln style decoration.
Specimens from the ruins show that a small number of green-glazed Ding kiln products were decorated with a variety of exquisite decorations such as inscriptions, markings, and stickers, and most of them were plain and without patterns.
In the early days, cosmetic clay was used, and the color was light green and verdant, which was pleasing to the eye and slightly different from the color of other kiln entrances.
Most of the decorations are made with Sancha pins, cushion cakes and mud rings, etc. There are no covered-burning varieties.
Ding kiln green glaze should be a low-temperature glaze fired in the kiln for the second time at about 800°C.
But as far as tires are concerned, we have never seen products with temperatures above 1100°C.
The reason may be that the boundaries of green-set biscuitware blanks must have a certain water absorption rate to ensure the adsorption capacity of glaze water.
At that time, Ding kiln firing technology could not solve the problem of secondary glaze hanging on biscuits fired at high temperatures of 1250°C.
Furthermore, when the raw tire is re-burned at high temperature, it is also easily broken.
Considering various factors, there was no high-temperature green tincture at that time.
Even if it exists occasionally, it is just a small amount of experimental products and immature products.
Therefore, due to technical limitations at the time, there was no Ding kiln variety that officially produced green-glazed high-temperature porcelain bodies.
In the Song Dynasty, only Guangrong County in western China fired high-temperature green glazed porcelain.
At the kiln entrances in the north and south, green-glazed pottery was mostly fired.
Ding kiln ruins, especially in Yanchuan District, are full of low-temperature green-glazed pottery.
Among the many Ding kiln green-glazed ceramic fragments, very few indeed have the characteristics of Ding kiln style carvings, thin bodies, and white bodies.
However, there is a significant gap compared with the high-temperature, white, and thin tires.
The origin of Ding kiln green glaze,
From the origin, the green glaze of the Han Dynasty, the multi-color lead glaze of the Northern and Southern Dynasties, the celadon glaze of the Sui Dynasty, the tricolor glaze of the Tang Dynasty, and the green glaze of the Song Dynasty should have an inheritance relationship.
Han green glaze is also a low-temperature lead glaze, but the glaze color is single, only green and yellow.
It is generally a glass glaze, and some glaze colors have poor transparency.
After more than two thousand years of geothermal and geological pressure, as well as water and soil infiltration, most of the glaze layers have changed.
Therefore, after being unearthed, silver-white crystals precipitate on the glaze, which is known as silver glaze in the world.
The glaze has less cracking.
After the further development of multi-colored glazes in the Northern and Southern Dynasties and celadon glazes in the Sui Dynasty, the colorful Tang tri-color glaze was formed in the Tang Dynasty.
The tri-color paintings of the Tang Dynasty are brightly colored, the enamel is transparent, the pieces are finely broken, and the texture is firmer than that of the Han Dynasty.
Tang-yellow glazed porcelain appeared in the Ding kiln system, with a finer body, a more transparent glaze, and the use of cosmetic clay.