The Thirteen Steps of Jian Zhan Kiln Firing Technique: Each Step Deserves Deep Exploration
Taking You into the Artistic World of Jian Zhan
Every Jian Zhan ceramic piece is born through thirteen production techniques:
Ore Selection, Ore Crushing, Washing, Proportioning, Aging, Mud Refining, Wedging, Wheel-throwing, Trimming, Bisque Firing, Glaze Application, Loading, and Kiln Firing
If we admire the natural beauty of Jian Zhan after its birth, and praise the endless color variations that nature has created in Jian Zhan's glaze, then the series of techniques before the birth of Jian Zhan is equally worthy of our understanding.
Many enthusiasts' knowledge of Jian Zhan is limited to "wheel-throwing, glaze application, and kiln firing"—these are indeed crucial three steps, but from raw clay to finished product, Jian Zhan undergoes many processes. Below we will introduce these thirteen steps for you.
Introduction to the Jian Zhan Manufacturing Process Below
Step 01: Ore Selection and Ore Crushing
Jian Zhan contains high iron content, making it impossible for other kilns to replicate it, and this cannot be achieved by other ceramic techniques. The main reason is insufficient iron content.
This uniqueness makes Jian Zhan stand out, and iron spots are a characteristic of Jian Zhan, as well as one of the standards for determining whether it is authentic Jian Zhan.
Why does Jian Zhan contain such high iron content?
Jian Zhan benefits from the unique geographical advantages of Jianyang. Whether selecting ore or glazing materials, Jian Zhan uses high iron-content ore from areas like Jianyang's Shuiqian and Houjiang villages, and the eastern Zhongcun area, specifically iron oxide and grass wood ash materials. This is also one of the reasons Jian Zhan is so precious.
The production difficulty of Jian Zhan is extremely high. Jian Zhan's glaze spots are produced at temperatures around 1300°C, and materials with such high iron content are susceptible to deformation and bubbling at high temperatures. This is also why we often see so many defects in Jian Zhan.
Why pursue high iron content despite these challenges?
However, if lower oxide iron-content clay or male clay with added oxide iron were used for production, this would increase product yield and fire resistance, seemingly solving some problems. But the glaze spots produced this way are generally very unsatisfactory. One must either not do it, or do it to perfection.
The lower the firing temperature, the higher the product yield and the simpler the kiln requirements with less iron. This is Jian Zhan's arrogance—only by pursuing perfection can it achieve such gorgeous colors and be loved by so many enthusiasts.
Step 02: Ore Crushing
The prepared clay and glaze materials are put into a mill or water tank for crushing processing, preparing for subsequent processes.
Step 03: Washing
Simply put, washing is mud washing. The crushed clay and ore materials are passed through water and filtered to settle, with the main purpose being to filter out impurities in the clay and ore materials.
It should be specially noted that some of the rough and fine glaze spots in some Jian Zhan pieces are identified at this washing stage. Since there is less water on the mouth's edge, it is more obvious that there are explosive sand particles on the mouth's edge. The coarser the glaze, the more obvious it is. This is commonly seen in some wood-fired Jian Zhan.
Especially for seniors' Jian Zhan collectors, you should know this is not a defect—embrace Jian Zhan with an open mind. Unlike other male ceramics that are so smooth and uniform, rough glaze and deep iron are the characteristics of Jian Zhan, and the glaze surface and rhyme are the charm of Jian Zhan.
Step 04: Proportioning
The traditional Jian Zhan glaze recipe uses natural iron ore combined with grass wood ash powder to be struck and then mixed into simple raw materials to fire exquisite Jian Zhan. This simple material composition seems unremarkable, yet Jian Zhan is created from the simplest and most original raw materials, firing into mysterious and beautiful crystals.
Different clay and proportions are matched with different glaze recipes. Jian Zhan has many flower varieties, one of which is the diversity of glaze proportioning. Who would have thought that monochromatic iron-water glaze would undergo endless color variations after firing?
As the saying goes: "Enter the kiln in one color, exit the kiln in ten thousand colors."
Step 05: Aging
Aging is storing the washed clay in a poorly ventilated, sunless environment. The main reason for doing this is to increase the clay's strength, uniformity, and plasticity.
Step 06: Mud Refining
Pour the processed mud slurry into cloth bags and press out water (using heavy objects or a press machine). Mud refining can be done by machine or by hand. Machine mud refining uses a vacuum mud refining machine; hand refining uses a hand mud wedge. The purpose of mud refining is to remove or reduce remaining air in the mud, making the material more uniform.
Step 07: Wedging
Divide all the mud into appropriate-sized mud blocks. Both hand and machine methods are acceptable, mainly to remove air from the mud, ensuring the material is tighter, easier to form, and preventing late-stage kiln firing cracks, breaking, and other issues.
Step 08: Wheel-throwing
After going through so many steps, Jian Zhan now has a basic shape, and many enthusiasts' basic knowledge of Jian Zhan production techniques starts with wheel-throwing. Wheel-throwing has very high technical requirements for craftspeople; the appeal and beauty of the vessel form greatly depend on the craftspeople's techniques.
"Hand-thrown Jian Zhan must have a soul."
When judging whether a Jian Zhan is hand-thrown, the thin-thick variations of the rim are also a very effective method. Because it's hand-made, the Jian Zhan's mouth diameter, shape, height, etc., won't be exactly the same, and this is the charm of hand-thrown pieces.
Many enthusiasts have this thought when watching craftspeople throw:
"The master throws so easily, can I do it too?"
What I want to say is, this is a huge misconception:
What appears simple wheel-throwing requires ten thousand times of practice, requires relentless day-and-night study and exploration, requires unwavering daily persistence, requires one's own understanding and pursuit of beauty, and requires boundless imagination.
Step 09: Trimming
After wheel-throwing, the basic shape of Jian Zhan is complete. Next comes making the vessel more refined and beautiful:
When the vessel body dries to about seventy percent, the craftspeople trim it to make it more neat and beautiful. Trimming mainly decorates: foot ring—foot ridge—shallow circular foot—inner circular foot—mouth rim—water line and so on.
It must be said that watching wheel-thrown trimming is very relaxing.
Step 10: Bisque Firing
Bisque firing refers to putting unglazed vessels into the kiln at relatively low temperatures for pre-firing, mainly to increase vessel hardness. Secondly, it removes some deformed and cracked vessels. This effectively makes the vessel body more solid, reducing defects. However, even so, under high-temperature conditions, deformation and cracking often still occur. The product yield of Jian Zhan is still very low.
Do all Jian Zhan go through this step?
Not all. For example, some craftspeople use wet glaze application methods, and this traditional firing method makes the glaze surface more aged, but the glaze water flow makes the originally easily deformable vessel body even more unstable, and while pursuing perfection, the defect rate will be higher.
Different firing methods yield different glaze feelings. The final glaze appearance's beauty or otherwise also depends on each enthusiast's judgment. As long as you feel it looks good, it is beautiful.
Step 11: Glaze Application
Finally arriving at the prelude to "enter the kiln in one color, exit the kiln in ten thousand colors," after the vessel body is cleaned of dust, glaze application begins.
"Glaze application skill" is very important in Jian Zhan, because glaze water's fluidity makes it extremely easy to stick the bottom if full glazing is used. The inside and outside of the vessel both need glazing. Often using hand-held circular foot dipping glaze methods, some craftspeople also use brush application methods. If full-body glazing is used, the product yield continues to decline.
Glaze application requires skill—craftspeople must control glaze application timing based on glaze water concentration, and also pay attention to glaze water thickness. If the glaze is too thick, the bottom easily sticks; if too thin, the crystal growth becomes too limited, making it difficult to achieve exquisite glaze spots. Making the glaze water more uniform is crucial, seemingly simple glaze application actually requires much technique.
Step 12: Loading
Place the vessels into the corresponding kilns, close the kiln doors, and make final preparations for firing. Equipment is ready to be sent.
Whether electric or wood kiln, placement is very critical—this is not superstition but science. Different positions have different atmospheres, different temperatures, and different fire trends, so the glaze effects fired are also different. Loading is also very particular.
Especially with through-heaven-dragon kilns—just placing staggered brick pillars in the kiln, in the narrow space, some kiln doors are still quite short. Craftspeople need to carefully place heavy brick pillars in the kiln, a step that appears easy but is actually extremely time-consuming and physically demanding.
Step 13: Kiln Firing
What is the full name of the work we usually call non-flame?
It is "the representative inheritor of Jianxi Jian Zhan kiln firing technique"
This final kiln firing step is also the most critical and most testing of the craftspeople's skill level in all steps.
The difference between wood and electric kilns lies in different heating methods: electric kilns use computers to control temperature; while wood kilns require manual fuel wood to control temperature.
Wood firing requires substantial manual labor and time investment, and is also affected by weather, humidity, and even the position of wood stacking inside the kiln. Combined with the large internal space of wood kilns, uneven temperature, and increased difficulty of temperature control, a realistic example: it's already very difficult to raise the temperature of such a large wood kiln to 1300°C evenly, and maintaining this temperature makes the firing difficulty imaginable. Wood kiln firing is like this—technique matters, but "luck" also matters.
Many people think electric kilns are simple because computers control temperature. In reality, the kiln itself cannot automatically maintain atmosphere; restoring still requires manual fuel wood control. The temperature elevation, stable maintenance, and stability are easier to control, but wanting to fire unique Jian Zhan requires extremely high attention to detail.
Jian Zhan firing—the real work lies inside the kiln. If the restoration timing, process, and frequency are not well controlled, the desired glaze colors cannot be fired. Once loaded, the craftspeople must concentrate fully, carefully controlling the restoration process and cannot leave the kiln for long periods to fire good Jian Zhan.
This leads to the question most new enthusiasts ask: "Is electric kiln better or wood kiln better?"
Wood-fired glaze surfaces are more inclined toward composite aged taste, oily and natural luster. By comparison, they are more oily, with flower patterns ever-changing, more inclined toward natural formation, more enduring and suitable for slow appreciation. While electric-fired glaze surfaces are more refined and beautiful, with uniform and dense bubble sizes tightly packed, crystals neat and prominent, precise and exquisite. Some glaze effects can currently only be completed by electric firing.
The different firing methods of wood and electric kilns have no absolute "better or worse," each with their own characteristics. "Beauty" has no absolute standard; it's more dependent on each enthusiast's inner judgment. As long as you feel it looks good, it is beautiful.
Having enumerated these thirteen steps, we believe enthusiasts will have deeper understanding of Jian Zhan. Each Jian Zhan comes hard-won, especially encountering glaze surfaces and patterns of perfection—these are priceless and unobtainable. We hope enthusiasts cherish them well.