Preparing Raw Materials
- Selection of Clay
- Unlike Baekja (White Porcelain), Celadon is made using sedimentary soil at the mountain valleys or shores which is crushed into tiny pieces through weathering and erosion. The clay used to make vessels should be well-sintered with excellent stickiness and high refractoriness.
- Filtering
- Soil harvested from nature has impurities such as stones and sands, which should be filtered.
- Dough and Maturity
- The filtered clay is molded to remove bubbles from particles. Then, this molded clay should be matured for a long period of time to maintain a certain level of moisture and increase stickiness.
Making Shapes
- Forming
- Methods to make Celadon include jiggering, the most common method to make ceramics, framing, the method to frame the shape of the vessels, and manual forming, the method to model after specific shapes.
- Drying and Patterning
- These formed vessels should be patterned to adjust the thickness of the vessels and cut the surface of the vessels after being dried properly.
Decorating with Patterns
- Decorating with Patterns
- When the vessels are dried starting to harden a little after forming and patterning, these vessels should be decorated with flowers, trees, birds, animals, and clouds on the surface.
Drying
- Drying
- The decorated vessels should be slowly dried. In the shady, indoor places inside and outside, and top and bottom of the vessels should be dried at the same speed to increase the strength and they can be piled easily inside the kilns. When these vessels are baked inside the kilns, the shapes can be well maintained.
Biscuit Firing
- Biscuit Firing
- The well-dried vessels with no glaze should be pre-baked inside the kilns around the temperature of 900℃. Biscuit firing is a process to obtain good colors in the rebaking after burning impurities inside and glazing the vessels.
Glazing
- Glazing
- The prebaked vessels should be cooled off for 4 to 5 days in the kilns and then glazed except for the damaged vessels. The glazing should add gloss to the surface to make vessels look better, along with being made with more intensity, and increase the practicality to prevent water and chemicals from being absorbed.
Rebaking
- Rebaking
- The glazed vessels are placed into the kilns again and should be rebaked at high temperatures of 1,200℃ and over.
The shortage of oxygen inside the kilns creates a reducing process by removing oxygen from oxidized steel in the vessels and glaze, which produces bluish Celadon. On the other hand, the method that constantly provides oxygen inside the kilns is called “burning oxidation,” which usually produces brownish Celadon.
Selection of Damaged Products
- Selection of Damaged Products
- Rebaked vessels are taken out of the kilns after being cooled off slowly. After checking these vessels thoroughly, damaged vessels are broken on the spot and only well-made Celadon are selected.