Chapter 1,103 The infinitely changing glaze colors
In the past, Chen Wenzhe was able to express the momentum and spirit of his works through porcelain sculptures. Now he can definitely go one step further and express a group of energetic and arrogant horses flawlessly.
Of course, it is just a simple shaping of the vessel, which is not much. The main thing is to apply the glaze.
The most amazing thing about Tang Sancai is its gorgeous and changeable glaze colors.
From the single-color glaze of the Han Dynasty, to the two-color glaze of the Sui Dynasty, to the three-color glaze of the Tang Dynasty, the wisdom of the predecessors is condensed.
The thickness of the glaze determines whether the blending of the two colors is harmonious and whether the flow is natural.
The endless changes in glaze colors have fascinated countless three-color artists.
The most successful aspect of Tang Sancai is its varied glaze colors and exquisite shapes.
Usually, the Tang Sancai we see are mostly green, yellow, white, and brown glaze colors, while blue and black glaze colors are less common.
The color of the glaze comes from the color reactions of different metal oxides in the glaze in different firing atmospheres of the kiln.
After testing the composition of the unearthed tri-color glaze, it was found that the main components of the tri-color glaze are lead silicate and metal colorants.
After hundreds of experiments, craftsmen in the Tang Dynasty successfully mastered the colors of different metal oxides and prepared glazes of different colors.
Add quartz and lead powder to the glaze, use lead oxide as a co-solvent, add appropriate amounts of copper, iron, cobalt, manganese, antimony, chromium and other ingredients, and then restore it to various colors after a temperature of 800℃~900℃.
For example, copper oxides appear green, iron oxides appear yellow or tan, cobalt oxides appear blue, and manganese oxides appear purple or black.
To be precise, green glaze is the addition of copper oxide to the glaze. In the oxidizing atmosphere of the kiln, the copper makes the glaze appear green;
Yellow glaze: Iron oxide is added to the glaze. In the oxidizing atmosphere of the kiln, the iron makes the glaze appear yellow, brown or brown-red;
White glaze: Since the glaze is made of porcelain clay and other raw materials, the porcelain clay contains more or less iron oxide components, and iron oxide can make the glaze appear cyan in a reducing atmosphere.
Therefore, through the processing and refining of the glaze, the iron oxide content in the glaze is reduced to a very low level, and the glaze after firing is white.
Black glaze: Increase the iron oxide content in the glaze. The higher the iron content (up to 8%) in the kiln oxidizing atmosphere, the darker the color after firing.
By adjusting the iron content, purple and black glazes can be obtained.
Blue glaze: The glaze uses cobalt as a colorant. In the reducing atmosphere of the kiln, cobalt makes the glaze appear blue.
In order to achieve certain special effects and produce special colors, craftsmen mixed the proportions of various metal minerals, and based on these glaze colors, they successfully fired brown-red, orange-yellow, light blue, and emerald green.
, dark green, sky blue, black, eggplant purple and other colors.
The flowing and blending of these glazes created the splendid and gorgeous style of the Tang Sancai art.
Of course, these are very simple to say, but how to mix the glaze color and what kiln temperature to fire it at still requires a lot of experience.
For example, what kind of glaze colors blend with each other to get the best effect?
We all know that when two colors merge, a new color will be formed.
This changeable and complex color will also form this discoloration effect during the process of blending and flowing of the glaze.
Here, experience is very important, and it can best reflect the unique painted pottery that interlaced and staggered glaze colors will eventually form.
In the end, the finished product will have primary color, compound color, and combined color.
At this moment, you can truly know what kind of complex color the staggered and staggered glazes will eventually form, and what kind of color they will ultimately have.
This is the most exciting aspect of tri-color pottery, because no one can tell clearly what any piece of work will eventually be like before it comes out of the kiln.
This is the final effect of having many glaze colors, and just because there are so many glaze colors, applying glaze is not simple.
There are two commonly used glazing methods for Tang Sancai, namely the zone glazing method and the pointillism glazing method.
The partitioned glazing method is to apply different glaze colors on different parts. Several glaze colors are applied on one object at the same time. The combination and blending of the glaze colors will produce a completely new effect.
The stippling glaze method is to use a brush to apply dots of uniform or inconsistent sizes, or dots, block-like dots, or strip-like lines on some parts of the object.
Some are neatly arranged, and some are natural and random.
After high-temperature melting, the glaze colors flow and blend to form a fantastic picture.
This kind of picture is full of virtual reality and mottled, like sunset or dreamland, forming a natural art style.
And after reaching this level, the production of each piece of Tang Sancai is only almost 90% completed. The last key step is to enter the kiln for firing.
Of course, because the firing conditions are different from those of porcelain, one kiln can only be filled with Tang Sancai. After all, the firing temperature is too low.
Therefore, when the first batch entered the kiln, Chen Wenzhe produced a large number of Tang Sancai.
However, there are not many classic types of vessels in it. Among them, the horses are mainly divided into glazed colors, including black glazed horses, yellow glazed horses, and red glazed horses. Of course, there are also red, green, and white ones.
As for more glaze colors, blending and firing to create colorful pottery horses, that's even more.
Of course, the same is true for other camel figurines, which always have glaze color instead of vessel shape.
This kind of Tang Sancai is troublesome to make, but once you have the mold, the stamping can be made very quickly. However, the shape of the finished pottery can only be exactly the same.
Chen Wenzhe adjusted some glazes of various colors and used them all.
He hesitated that it would be troublesome to make human figurines, camel figurines, horses and other types of utensils, so in the end, in order to fill the kiln, Chen Wenzhe directly used a pottery cart to pull out a large number of ordinary utensil embryos.
This is actually the wheel system in Tang Sancai, which is suitable for making vessels with round bodies.
Such as cups, plates, bowls, saucers, beans, bottles, stoves, pots, cans, etc. in daily utensils.
However, there are also some oblate, ellipsoid, irregular and other objects that use the molding method.
After all these are completed, they cannot be put into the kiln immediately, because each piece of shaped utensil needs to be thoroughly dried in the shade before being bisque fired. This can avoid carcass deformation and cracking during high-temperature firing.
This is how Tang Sancai was made. It was not fired in one go, but was fired in two steps.
The first step is biscuit firing. First, the biscuit body is made and then fired in the kiln.
In this first roasting, the carcass is burned hard at a temperature of about 1000°C to 1100°C. After being taken out, it is glazed and then fired again in the kiln.
After entering the kiln and undergoing glaze firing at a temperature of 800℃~900℃, the glaze on the carcass begins to melt, and the glaze juice melts, flows and infiltrates with each other, forming colorful colors.
The colorful colors at this time are definitely not flashy, unnecessary, and chaotic glaze colors, but the effect that the author wants through experience and specially prepared glazes.
This is the most exciting step in the firing of Tang Sancai, and it is also the most critical step.
It is also in this step that the quality of a Tang Sancai work is determined, and if you want to do this step well, you definitely need technology and experience.