From Raw Materials to Bisque Firing: How Ceramic Tableware Bodies Are Made

Before a ceramic plate, bowl, mug or teapot receives its glaze, decoration and final firing, it must first pass through one of the most important stages in ceramic manufacturing: the transformation from raw minerals into a stable bisque-fired body.

For many daily-use ceramic tableware products, a conventional two-firing process is used. The first firing is known as bisque firing, or biscuit firing. At this stage, the ceramic body has not yet been glazed. The purpose is to remove remaining moisture and organic matter, strengthen the body, and create controlled porosity so that glaze can be applied evenly during the next stage of production.

At Donglin Homeware, understanding and controlling every step before bisque firing is essential because many defects found later in glazing or final firing can actually originate much earlier—during raw material preparation, forming or drying.

This article takes you through the complete ceramic tableware manufacturing process from raw materials to bisque firing.

1. Raw Material Preparation: Building the Ceramic Body

The quality of ceramic tableware begins long before the product takes shape.

A typical white ceramic body for daily-use tableware is formulated from several mineral components, commonly including:

Kaolin, which contributes plasticity and whiteness; feldspar, which acts as a flux during firing; and quartz, which provides structural support and helps control shrinkage.

The exact formulation depends on the required ceramic body, firing system, whiteness, translucency, strength and product application.

Once the raw materials are weighed according to the body recipe, they enter the slurry preparation process.

Ball Milling

The raw materials are mixed with water and placed into a ball mill.

During milling, mineral particles are progressively reduced in size and thoroughly dispersed. This improves the uniformity of the ceramic body and helps ensure that different raw materials are distributed consistently throughout the slurry.

Particle-size control is important. Insufficient milling can leave coarse particles in the body, while excessive or poorly controlled milling may affect rheology and forming performance.

Screening and Iron Removal

After milling, the ceramic slurry passes through vibrating screens to remove oversized particles and unwanted impurities.

Magnetic separation is also used to reduce iron contamination.

Even very small metallic impurities can create dark spots or visible defects after firing, which is particularly undesirable for white ceramic tableware.

Filter Pressing

The prepared slurry is then transferred to a filter press.

Under pressure, excess water is removed and the slurry is converted into relatively firm clay cakes.

This step changes the material from a fluid suspension into a workable ceramic body suitable for further preparation and forming.

Aging

The clay cakes are normally allowed to rest in a controlled or enclosed environment.

During this aging period, moisture becomes more evenly distributed throughout the body and the clay develops more stable plasticity.

Depending on the factory process and ceramic body, aging may last from several days to longer periods.

Vacuum Pugging

Before forming, the clay passes through a vacuum pug mill.

Vacuum treatment removes trapped air from the body while further homogenizing moisture and texture.

This is an important preparation step because internal air pockets can contribute to cracking, weak areas or forming defects.

The result is a dense, homogeneous clay body ready to become ceramic tableware.

2. Forming: Turning Prepared Clay into Greenware

Once the ceramic body has been prepared, it moves to the forming department.

At this stage, the product is still unfired and is known as greenware or a green body.

Different tableware shapes require different forming methods.

Roller Forming

Roller forming is widely used for high-volume production of items such as:

plates, bowls, dishes and certain cup forms.

A measured portion of prepared clay is placed into a plaster mold. A rotating forming head then presses and shapes the clay against the mold surface.

Because the process offers good repeatability and efficiency, roller forming is one of the most common methods used for mass-produced ceramic tableware.

Slip Casting

More complex or hollow shapes—especially teapots, pitchers, irregular serving pieces and decorative forms—are often produced by slip casting.

Liquid ceramic slip is poured into a plaster mold.

The plaster absorbs water from the slip, causing a layer of ceramic material to build up against the mold wall. Once the required wall thickness has developed, excess slip is drained away.

After partial drying, the piece can be removed from the mold.

Dry Pressing

Dry pressing uses ceramic powder that is compressed under pressure inside a mold.

Although widely used in some ceramic industries, it is less common for conventional daily-use hollowware and tableware than roller forming or slip casting.

After forming, the newly shaped ceramic article is still relatively soft, moist and fragile.

The next stages are therefore crucial.

3. Initial Drying, Trimming and Greenware Inspection

Freshly formed ceramic pieces cannot immediately enter the kiln.

They must first gain enough strength to be handled without deformation.

Mold Drying and Demolding

For plaster-mold processes, the body is normally allowed to dry partially while still supported by the mold.

This controlled initial drying gives the greenware enough rigidity for safe removal.

Demolding too early may lead to deformation, while excessive drying inside the mold can cause stress or cracking.

Trimming

After demolding, excess clay and forming marks are removed.

Depending on the product, workers or trimming equipment may refine:

the foot ring, rim, edges, seams and overall roundness.

This stage is particularly important for products such as dinner plates, bowls and cups, where dimensional consistency directly influences stacking and table presentation.

Greenware Cleaning

The surface is then carefully cleaned.

A damp sponge may be used to remove fine clay particles, dust and trimming residue, while loose material inside hollow pieces is also removed.

Even small particles left on the body can later create surface defects.

Greenware Inspection

Before final drying, semi-finished products are inspected again.

Pieces showing cracks, damaged rims, severe deformation or other obvious defects are removed before they consume additional kiln and production capacity.

Quality control therefore begins well before glazing or decoration.

4. Controlled Drying: One of the Most Important Anti-Cracking Stages

Drying may appear simple, but it is one of the most sensitive steps in ceramic manufacturing.

Fresh greenware contains a substantial amount of free water.

If water leaves the ceramic body too quickly or unevenly, different areas shrink at different rates. This can cause:

warping, rim deformation, body cracks or separation at joined areas.

For this reason, ceramic products normally undergo progressive controlled drying rather than sudden high-temperature drying.

The process generally begins under relatively mild temperature and higher humidity conditions. Humidity is gradually reduced while temperature is carefully increased.

By the end of the drying cycle, the green body must contain very little residual moisture.

In many production systems, the target is around below 1% residual moisture before kiln loading, although the exact specification depends on the ceramic body, product shape and firing system.

This control is critical.

If excessive free water remains inside the body when it enters the kiln, rapidly expanding steam can create severe cracking or even cause pieces to burst during heating.

For large pieces and products with uneven wall thickness, controlled drying becomes even more important.

5. Kiln Loading and Bisque Firing

Once the greenware has been fully dried and inspected, it is ready for its first firing.

This is the bisque firing stage.

Products are carefully positioned on kiln furniture with appropriate spacing between pieces. Depending on the product design, kiln type and contamination requirements, larger or more sensitive pieces may also be protected using suitable kiln furniture or saggers.

Correct kiln loading affects not only production efficiency but also heat circulation and firing consistency.

What Happens During Bisque Firing?

Bisque firing is not simply a matter of heating the product to one temperature.

Several physical and chemical transformations occur as the kiln moves through its firing curve.

Depending on the ceramic body and manufacturing process, bisque firing is commonly carried out in the region of approximately 800–950°C. Some hard porcelain production systems may use bisque temperatures around 850–900°C, but actual firing curves must always be matched to the specific body formulation and factory process.

Tunnel kilns are frequently used for high-volume ceramic tableware production because they allow continuous and controlled firing.

After the required firing cycle and holding period, the ware is gradually cooled before being removed from the kiln.

Rapid cooling is avoided because excessive thermal stress may produce cracking or other defects.

6. What Is a Bisque-Fired Ceramic Body?

After the first firing, the product has changed significantly.

The fragile dried greenware has become a much stronger bisque body.

It can now withstand normal factory handling more reliably and is suitable for subsequent glazing processes.

At the same time, the body remains porous.

This porosity is intentional.

When glaze slurry is applied to the bisque body, the porous ceramic surface absorbs water from the glaze suspension and allows a controlled glaze layer to develop on the surface.

This helps produce more consistent glaze coverage.

However, an important distinction should be made:

bisque ware is not finished ceramic tableware.

At this point the body has not reached full vitrification and still absorbs water. It must continue through glazing, glaze firing and—depending on the design—additional decoration processes before becoming finished tableware.

7. Bisque Inspection Before Glazing

After cooling and unloading, the bisque ware undergoes another quality inspection.

Typical issues checked at this stage include:

cracks caused during firing, deformation, surface contamination, kiln debris and other defects that could affect glazing or final product quality.

Only qualified bisque pieces proceed to the next production stage.

From here, the process may continue into:

glazing → glaze firing → decal application → decoration firing → inspection → packaging

depending on the material, design and manufacturing route.

This staged inspection approach helps prevent defective semi-finished products from progressing further through production.

Why the Pre-Bisque Process Matters to Buyers

For importers, retailers and brands, the visible decoration is only one part of ceramic quality.

A well-manufactured ceramic product depends on the entire body-production process underneath the glaze.

Proper raw material preparation helps reduce impurities. Vacuum pugging reduces trapped air. Stable forming improves dimensional consistency. Controlled drying helps prevent cracking and deformation. Correct bisque firing provides the strength and porosity required for reliable glazing.

In other words, many quality characteristics that eventually appear in a finished dinner plate, bowl or mug are already being determined before the first firing is completed.

That is why ceramic manufacturing should be viewed as a connected process rather than a series of isolated production steps.

From Greenware to Finished Tableware

The journey from minerals to ceramic tableware is a balance between material science, forming technology, kiln control and experienced workmanship.

At Donglin Homeware, we support OEM and ODM ceramic tableware development for international importers, retailers, brands, distributors, gift companies and hospitality customers.

Depending on the project, customization can include body material, product shape, mold development, glaze color, decal artwork, logo application, decorative techniques and packaging solutions.

Whether you are developing a dinnerware collection, ceramic mugs, tea and coffee ware or coordinated serving pieces, the process begins with building the right ceramic body and controlling each production stage carefully.

Have a ceramic tableware concept in development?

Share your preferred style, product category, intended market, brand or logo concept, shape expectations and special decoration requirements with our team. We can help evaluate the project from sampling and ceramic production through decoration, packaging and bulk manufacturing.

Donglin Homeware — OEM & ODM Ceramic Tableware Manufacturing for Global B2B Buyers.

Email: homeware@szdonglin.com

What's App / Tel: +86 134 3474 6080

Website: www.szdonglin.com