Mei Dingzuo of the Ming Dynasty's "Jade He Ji·Yi Jiao": "Ruli couch, emerald floor, hand-rolled pearls with jade hooks."
Obviously, in ancient times, colored glaze was made into various treasures.
In ancient times, colored glaze was a valuable work of art for two reasons.
First, the material of ancient colored glaze is special, and its production process is quite complex.
It comes in the fire and goes out in the water. It takes dozens of processes to complete.
Some light production processes take ten to twenty days, and they mainly rely on manual work.
It is quite difficult to grasp each link, and the difficulty of grasping the heat can be said to depend half on skill and half on luck.
For just one item, the yield is only 70%.
More importantly, ancient colored glaze cannot be recycled.
In other words, once a slight problem occurs, dozens of days, dozens of processes, and many people's efforts will be immediately wasted.
Secondly, colored glaze is not only a material, but also a cultural product. More importantly, there are no two identical colored glaze products.
The main reason is that the production process is lengthy. From conception, design, sculpture, firing, fine repair, polishing to completion of the work, it requires forty-seven delicate and cumbersome manual processes to complete.
Then there is the manual production, and workers must master the technology before they can operate it.
Each process has its own variable factors, and requires repeated experiments during the process. The colors of the works are not the same, and the production is extremely difficult.
In ancient glaze production, one mold can only be used to bake one work and cannot be used twice.
Large and complex works even require multiple mold openings and firings to complete.
The low success rate makes the work more valuable and precious.
In fact, there was another difficulty in ancient times, which was high-temperature firing.
In ancient times, it was not easy to melt selected raw materials into various colored crystal glasses at temperatures above 1400c.
What's more, after multiple selections and cleanings, they are placed in the mold according to the proportion of materials used in the work, and strict rising and cooling curves are set.
During this process, the furnace temperature must be controlled within 1000c±5c.
The firing process lasts for more than 15 days, making the crystal raw materials precise down to every detail.
This ensures that the work is exquisite, three-dimensional, realistic, streamlined and clear.
However, the cost was too high, so the current glass production process emerged.
Today's thermoformed glaze, which is the production process of traditional glaze firing techniques, is no longer too complicated.
The first step is to mix the materials. The various pigments required are put into the furnace for smelting, and the molten glass is rotated on the iron rod.
The next step is to select the materials, and use a 1.5-meter-long blow tube to take out the colored glaze from the traditional furnace with a temperature of more than 1,400 degrees.
The next step is blowing. After taking it out of the furnace, it is constantly rotated and shaped. The temperature of the glass taken out of the furnace is high. If you master the softness of the melted glass, it will be shaped in a few seconds.
Next is shaping. During the shaping process, the masters need to blow with the blow tube in their hands to ensure the shape of the glass. Since the scale is difficult to grasp, the yield is extremely low.
The last step is annealing. After the glass is formed, the masters put the fired glass into the heat preservation kiln.
The temperature at the entrance of this kiln is more than 500 degrees, and it is kept warm for 4 days.
If the glass bottle body does not explode, it means that the glass has cooled down and taken shape.
When Chen Wenzhe was a child, he saw this kind of craftsmanship in a small glaze factory in his hometown, and thought it was very simple.
Of course, this does not include the ingredients for various colored glasses, because apart from the craftsmanship, the formula is the most difficult.
Today's glass production technology has developed to a very high level.
If he doesn't accumulate technology, Chen Wenzhe really doesn't have the confidence to compete with the top domestic glass manufacturers.
Therefore, he planned to learn all kinds of crafts.
For example, the ancient method of making lost-wax glaze is actually not difficult to think about.
However, making colored glaze with this process requires a bit of trouble and high cost.
The main cost is making the mold, and only one product can be produced at a time.
To make lost-wax glass, the first step is creative design, which means expressing creativity through graphic design artwork.
Then there is prototyping, sculpting a three-dimensional model based on the artwork.
The next step is to make a silicone mold and apply silicone evenly on the surface of the model. After the silicone solidifies into a silicone mold, plaster is still needed to fix it.
After that it will be easy, just follow it step by step.
With a suitable mold, the wax pattern is poured.
Prepare the wax slurry, pour the hot melted wax into the silicone female mold, wait for it to cool down naturally and then remove the wax mold.
Remove the cold-cut wax mold from the silicone plaster mold.
Trim the wax pattern all the way. Cold cutting can easily cause the wax pattern to shrink and deform. The mold line traces left when the mold is removed must be carefully trimmed with tools.
After completing this step, a plaster mold will be made again.
Prepare the correct proportion of refractory gypsum, pour and embed it outside the modified wax mold to form a wax-containing gypsum mold.
Next, it's still dewaxing, but this time it's steam dewaxing.
The entire wax-containing gypsum is placed in a dewaxing machine and heated with steam. After dewaxing, it becomes a refractory gypsum negative mold.
Once the mold is made, the raw materials are selected.
In order to accurately control the proportions of various colors and the flowing beauty, glass raw materials of specific colors and sizes need to be selected according to the shape and design, and the distribution positions of the color blocks must be arranged.
After that, it is put into the furnace for sintering, and after the mold is cleaned and dusted, the entire plaster mold and the prepared glass frit are put into the furnace and slowly heated.
This will cause the hot melt-softened crystal glass, such as maltose, to slowly flow into the plaster mold to form.
After this step is completed, the plaster mold must be removed and the cold-cut glass rough embryo must be taken out.
The rough embryo still needs to be cut and repaired, mainly to cut and repair the excess glass on the rough glass embryo and the grouting port.
The next step is to trim, such as using coarse and fine abrasive sand to smooth the sprue of the crystal glass.
There is also cold workmanship, which involves careful carving with diamond pens and other tools to make the surface of the work appear more even and delicate.
The material of colored glaze is artificial crystal glass.
Its characteristic is that it has a high refractive index against light, so it can show a crystal clear effect.
With the cooperation of light, its artistic characteristics can be fully expressed.
As colored glaze, it is not only a work of art but also a religious object.
The works made through casting technology are highly expressive, rich in layers, exquisite and delicate, especially the flow of colors is unpredictable, either passionate or subtle, and each piece is different.
Appreciating the effect of light and shadow, especially the refraction of light at different angles, thickness and color, can present a three-dimensional visual effect.
In the process of appreciation, you will find that the glass cannot be made too transparent.
In other words, the transparency of colored glaze should not be too pure or too bright.
Good colored glaze needs to have a certain difference in level and smoothness, otherwise it will lose its dynamic vitality and beauty.
By grasping all these special features, the glass produced will not be too bad.
Besides, due to ancient craftsmanship, no two pieces of colored glaze are exactly the same in the world.
The so-called "Tiangong is self-contained" refers to the singleness of colored glaze products.