Celadon is a large series and the origin of porcelain, so it is naturally very important.
After the Song Dynasty, the charm of celadon became even more dominant.
Among the five famous kilns in the Song Dynasty, four were related to celadon.
Among them, the story of Longquan kiln is even more legendary.
This kiln that existed since the Three Kingdoms and Jin Dynasties was still unremarkable until the Northern Song Dynasty.
However, after the fall of the Northern Song Dynasty, Longquan kiln combined southern and northern arts and created a peak in the history of celadon in my country.
Mature firing technology and dignified and elegant style make Longquan kiln famous all over the world.
The successful firing of pink celadon glaze and plum celadon glaze is even more ingenious, leaving a glorious page in the history of Chinese porcelain.
From the perspective of modern technology, the firing and development of celadon is a particularly important step in the history of Chinese ceramics. It is a process from accidental discovery to deliberate utilization of technology.
This is the result of technological innovation in which the iron element in the porcelain body glaze is constantly increasing and decreasing.
But from the imagination of beauty, we are more willing to believe that the intention of cyan must be too ethereal, so the ancients used a unique method to solidify it on the utensils, so that everyone in the world can appreciate the beauty of cyan.
The rise of color into a means of artistic expression was accomplished unconsciously by the ancients.
When the ancients discovered that porcelain was more than just a vessel for use, the charm of art emerged from it.
In the chaos of nature, a ray of green is often pleasing to the eye. This awakening is the forerunner of celadon art.
The predecessors of all celadon are things that the ancients had no choice but to do.
The iron content of the glaze determines the color of the celadon glaze. However, ancient craftsmen were unable to master the coloring conditions for a long time and were in trouble.
After that, in a lot of repetitive work day after day, opportunities appeared by chance again and again, waiting to be captured by smart people.
The hard-working kiln workers in ancient China were the unknown wise men.
After that, various kinds of celadon appeared, and the leader among them was naturally Longquan celadon.
Chen Wenzhe's eyes narrowed when he heard about Longquan Celadon. Is this because he is following his fancy?
You must know that his best skill is imitating Longquan celadon!
He really didn't expect that Wu San would turn the topic to Longquan celadon of the Southern Song Dynasty.
When it comes to this, isn't he afraid that the class might break his own foot?
Or is this just playing into his own favour?
Sure enough, Wu San was just the beginning, and it was Lao Zhou and Lao Li who analyzed Longquan celadon technology in a simple and in-depth manner.
Just hearing it, Chen Wenzhe expressed his admiration.
If he had not seen the authentic palette unearthed from the Longquan kiln, how would he know what raw materials were used in the Longquan kiln back then?
The two old men in Jingzhen are different. They don't have the means to cheat, but they have a sufficiently complete inheritance.
Due to the geographical location of Longquan kiln, the soil used for making porcelain is naturally rich in quartz, kaolin, sericite and other minerals.
This is natural porcelain clay and glaze!
These substances can make the tire color appear white or off-white in the reducing atmosphere of the kiln.
Gu Jie
And if a certain amount of purple gold clay is added to the porcelain clay, the color of the porcelain body will appear black. This is also the reason why the porcelain body color of Longquan kiln is black and white.
Among them, there are some key points, which can also be said to be small details, such as the color tone of the tire, which has a certain foil effect on the glaze color.
If you didn't make this by yourself, or if you haven't fired many Longquan kiln porcelains, it would be difficult to discover this little experience.
The color of Longquan kiln porcelain is mainly turquoise, and the color is darker. This is because a certain amount of purple gold soil is added to the tire soil formula, thereby increasing the depth of the tire color.
Purple gold soil is a kind of soil material with a high iron content, which brings unique glaze color to the porcelain of Longquan kiln.
Therefore, what Longquan kiln is most proud of is its elegant and jade-like glaze color.
How to fire such top-notch glaze color is the biggest difference between the Northern Song Dynasty and the Southern Song Dynasty!
During the Northern Song Dynasty, the glaze used in Longquan Kiln was lime glaze.
So, what is lime glaze?
Previously, Chen Wenzhe had seen through his works the composition of glazes used in the Longquan Kiln of the Southern Song Dynasty when making porcelain.
Now after Lao Zhou's explanation, he has a clearer understanding of what can become glaze, and what kind of minerals and raw materials can be used to synthesize good glaze.
The glaze itself is a slurry-like substance made from quartz, kaolin, plant ash and other mineral raw materials in a certain proportion and through corresponding processes;
Apply glaze slurry to the surface of the embryo, and after firing at high temperature, a glassy substance will be formed on the surface of the object, which is called "glaze".
Lime glaze refers to a glaze whose main glaze component is limestone (calcium carbonate, silica, etc.).
Due to its own composition, lime glaze has a low viscosity during high-temperature firing and glaze flow is prone to occur. Therefore, porcelain using lime glaze usually has a relatively thin glaze layer.
The Longquan kiln in the Northern Song Dynasty used lime glaze, so in terms of product glaze color, except for the conventional green-green color, there was nothing particularly outstanding.
However, after the time entered the Southern Song Dynasty, Longquan kiln craftsmen invented the lime alkali glaze and created the popular pink celadon glaze and plum celadon glaze products, which made Longquan kiln porcelain instantly famous and well-known.
Chen Wenzhe naturally knew about lime alkali glaze, and he knew even more clearly that there was not necessarily no lime alkali glaze during the Northern Song Dynasty, because he suspected that Ru kiln porcelain was fired with this kind of glaze.
Of course, the lime alkali glaze used in the Northern Song Dynasty, or in other words, the technique of using lime alkali glaze, was different from that in the Southern Song Dynasty, which resulted in the unique beauty of Ru kiln porcelain.
Now he is very sure that the thick glaze of Ru kiln porcelain should be related to lime alkali glaze.
So what exactly is the lime alkali glaze? People in Jingzhen have also studied it clearly.
Lime alkali glaze is a new type of glaze made on the basis of lime glaze by adjusting some of its components and proportions.
For example, increasing the content of metallic potassium and reducing the content of calcium oxide, etc.
In this way, the lime glaze was finally improved into a calcium-potassium glaze.
Due to the increase in alkali metal content, the viscosity of the glaze increases and the fluidity decreases under high temperature, thus forming a thick glaze layer.
Longquan kiln porcelain after the Southern Song Dynasty generally has a thicker glaze layer, which is due to the use of lime alkali glaze.
At the same time, multiple glazing methods were also used in the firing process, that is, biscuit firing - glazing, then bisque firing - glazing, repeated three to four times, and finally a thick glazed celadon that was as warm and moist as jade was fired.
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These techniques, coupled with the agate-glazed Bao-firing technique, can finally produce Ru kiln porcelain, right?
Calculated in this way, the invention and application of lime alkali glaze is a huge creative improvement in the color of celadon glaze.
It gives the surface of the porcelain a glaze effect with a sapphire-like texture.
Its glaze layer is thick and even, just like natural jade. Isn't this also a characteristic of Ru kiln porcelain?