From Bisque to Glaze: How Ceramic Mugs and Tableware Are Decorated and Glazed

A ceramic mug may look simple when it reaches the retail shelf, but between the first firing and the finished product lies one of the most important stages in ceramic manufacturing: decoration and glazing.

For many daily-use ceramic mugs, plates, bowls and serving pieces made through a conventional two-firing process, the first-fired ceramic body is known as bisque ware or biscuit ware. At this stage, the body is strong enough to handle but remains porous and absorbent.

What happens next depends largely on the design.

For a plain white or solid-color product, the bisque body may proceed directly to glazing. For underglaze decorated tableware, the artwork is applied to the bisque body first, followed by a transparent glaze and high-temperature glaze firing.

This order is important:

Bisque inspection → surface preparation → underglaze decoration → drying → glazing → foot cleaning → glaze inspection → glaze firing

By contrast, many on-glaze decorations are applied only after the glazed whiteware has already completed its glaze firing.

Understanding this distinction helps importers, retailers and brands select the right decoration process for durability, appearance, food-contact applications and target price positioning.

1. Preparing the Bisque Body Before Decoration or Glazing

Before any artwork or glaze can be applied, the bisque ware must first pass another inspection.

Although the body has already survived the first firing, defects may still be present. Typical checks include cracking, deformation, pinholes, kiln debris and surface contamination.

Pieces that fail inspection are removed before additional processing.

The surface is then cleaned.

Because bisque ware is porous, fine dust left from handling, grinding or kiln unloading can interfere with glaze adhesion. Depending on the product and production setup, compressed air, brushing, wiping or controlled light washing may be used to remove loose particles.

This step is more important than it may appear.

Dust, oil or contamination on the bisque body can contribute to defects such as crawling, pinholes, bare spots or poor glaze coverage later in production.

The moisture condition of the bisque body also needs to be controlled. An extremely dry porous body may absorb water from the glaze too rapidly, making it harder to achieve an even coating. In some production systems, the ware may therefore be lightly conditioned before glazing.

The exact moisture-control method depends on the ceramic body, product shape and glaze formulation.

2. Underglaze Decoration: Artwork Applied Before Glazing

When the decoration needs to sit beneath the finished glaze surface, the artwork is applied to the bisque body before the transparent glaze.

After firing, the decoration becomes visually integrated with the glazed ceramic surface rather than sitting above it.

This makes underglaze decoration particularly attractive for many daily-use tableware programs where buyers want a smooth surface and strong resistance to normal use.

Common underglaze decoration methods include underglaze decals, hand painting, pad printing and digital printing.

Underglaze Decal Application

Underglaze decal is especially useful for repeating seasonal or coordinated artwork across multiple ceramic shapes.

A typical decal process begins by conditioning or soaking the decal according to its specification so that the printed decoration can be transferred from the carrier sheet.

The artwork is then carefully positioned on the bisque surface.

A soft scraper, roller or similar tool is used to remove trapped water and air while ensuring the decal follows the curvature of the ceramic body.

This is particularly important on products such as mugs, bowls, teapots and curved serving pieces.

After application, the decorated bisque must dry thoroughly before glazing.

Once covered with a compatible transparent glaze and correctly fired, the design is protected beneath the glaze surface.

For Christmas collections, botanical tableware, illustrated mugs and coordinated seasonal ranges, this technique can be useful because one artwork story can be extended across:

plates, bowls, mugs, cups and saucers, teaware and serving pieces.

For food-contact ceramic products, however, decoration method alone does not establish compliance. The complete product—including body, glaze, pigments and firing conditions—should be tested according to the requirements of the destination market.

Underglaze Hand Painting

For smaller quantities, artisan-style collections or premium customized programs, underglaze pigments can also be applied by hand.

The painter works directly on the bisque surface using ceramic colorants formulated for the intended firing system.

After glazing and firing, the brushwork appears beneath the glass-like glaze layer.

This process can create a more individual visual character than mass-applied decoration and is suitable for selected premium or craft-oriented ranges.

Because ceramic colors may react differently at high temperatures, the final fired color must be confirmed through sampling rather than judged only from the unfired pigment.

Pad Printing for Curved Ceramic Surfaces

Pad printing is another efficient option for certain mugs and curved ceramic forms.

A flexible silicone pad transfers the design from the printing plate onto the ceramic surface.

Because the pad can conform to curved shapes, it is useful for repeated logos, small motifs and controlled decorative areas.

For OEM and private-label ceramic mugs, pad printing can offer good repeatability when the design and product geometry are suitable.

Digital Underglaze Printing

Digital printing gives manufacturers additional flexibility for artwork development.

Instead of relying entirely on conventional printing screens or hand-painted decoration, compatible ceramic inks can be digitally applied according to the production system.

This can be particularly useful for:

rapid sampling, shorter development cycles, smaller customized runs and more complex artwork.

The exact process, color range and firing performance depend on the equipment, ink system, glaze and ceramic body.

For brands developing multiple seasonal collections, digital production can therefore be a useful part of the sampling and product-development toolkit.

3. The Correct Sequence for Underglaze Tableware

For a typical underglaze ceramic product, the basic manufacturing logic is:

Bisque ware → cleaning → underglaze decoration → complete drying → transparent glaze → glaze drying → foot cleaning → inspection → glaze firing

The transparent glaze is a critical part of this system.

It seals the porous ceramic body while creating the final smooth, glass-like surface associated with finished tableware.

When the glaze, pigment, ceramic body and firing curve are properly matched, the decoration becomes an integrated part of the finished ceramic surface.

4. What Is Ceramic Glaze Made From?

Ceramic glaze begins as a liquid suspension, often resembling a milk-like slurry.

Depending on the formulation, glaze materials may include combinations of:

feldspathic materials, silica, clay components, fluxes and other functional additives.

The formulation determines characteristics such as:

transparency, gloss, melting behavior, surface feel, color response and firing compatibility.

For decorated tableware, a transparent glaze allows the underglaze artwork to remain visible.

For other collections, the glaze itself may create the design effect.

Examples include:

colored glaze, matte glaze, reactive glaze, crystalline effects and other specialty surfaces.

The glazing method must therefore be matched to both the product shape and the required finish.

5. Four Common Glazing Methods in Ceramic Tableware Production

Different ceramic forms require different ways of applying glaze. In mass production, four methods are especially common.

Dipping

Dipping is one of the most familiar glazing methods for mugs, bowls and similar products.

The porous bisque piece is immersed into the glaze slurry and then removed at a controlled speed.

As the body absorbs water from the glaze suspension, solid glaze material remains on the surface.

Immersion time, glaze viscosity, specific gravity, body absorption and withdrawal speed all influence the final coating.

In some production systems, immersion may last only a few seconds, but the correct value must be established for the individual body-and-glaze combination.

One area must remain glaze-free:

the foot.

Any glaze left on the part that contacts the kiln shelf can melt during firing and bond the product to the kiln furniture.

The foot ring is therefore wiped or cleaned before firing.

6. Waterfall Glazing for Plates

For high-volume production of plates and other flatware, automated waterfall glazing or flow-coating systems can provide efficient and repeatable coverage.

The bisque piece travels along a conveyor while glaze flows across the surface in a controlled curtain.

Depending on the production line, different surfaces may be glazed in separate stages.

The advantage is consistency.

When properly controlled, automated glazing can deliver a stable coating across large quantities of plates and reduce variation between pieces.

This makes it particularly suitable for mass-produced dinnerware programs.

7. Spray Glazing for Special Shapes and Decorative Glazes

Not every piece can be efficiently dipped or passed through a glaze curtain.

Irregular servingware, complex molded forms and certain specialty glaze effects may be better suited to spray glazing.

Inside a controlled spray booth, glaze is atomized and applied in multiple passes.

The operator or automated system can control coverage in specific areas and gradually build the required glaze layer.

Spraying is especially useful for some:

colored glazes, gradient effects, reactive glazes and crystalline-style surfaces.

Because overspray and glaze thickness influence the finished result, production control and sampling are particularly important.

8. Internal Glazing for Mugs and Hollowware

Mugs, pitchers, jugs and similar hollow pieces need complete glaze coverage on their inner surfaces.

One common technique is pouring glaze into the vessel and rotating or tilting the piece so the slurry coats the entire interior.

The excess is then drained.

After the inside has been coated, the outside can be glazed using dipping, spraying or another suitable process.

For drinking vessels, consistent interior glazing is particularly important because the inside surface comes into direct contact with beverages.

9. Controlling Glaze Thickness

Glaze application is a balance.

If the glaze coating is too heavy, defects can include:

flowing glaze, pooling, pinholes or uneven surfaces.

If it is too light, the finished ceramic may show:

thin areas, exposed body, uneven gloss or insufficient coverage.

For many daily-use ceramic systems, fired glaze thickness may fall roughly around the 0.25–0.40 mm range, but this should not be treated as a universal specification.

Actual targets vary according to:

ceramic body, glaze formulation, application method, firing temperature, product shape and required finish.

For OEM or ODM projects, glaze specifications should therefore be confirmed through production trials and approved samples rather than assumed from a general industry value.

10. What Happens After Glazing?

Once the glaze has been applied, the piece is not ready for the kiln immediately.

First, excess water must evaporate.

As it dries, the wet glaze becomes a dry, powder-like coating attached to the porous bisque surface.

The foot ring is then wiped clean.

Operators inspect the ware for problems such as:

missing glaze, contamination, bubbles, pinholes, uneven coating or glaze accumulation.

Only approved pieces proceed to kiln loading.

The ware is then fired at the glaze-firing temperature specified for the ceramic body and glaze system.

For some new bone china and reinforced porcelain manufacturing systems, final firing may fall approximately within the 1220–1300°C range, although actual production temperatures must be determined by the specific body, glaze and factory firing curve.

During this firing, the glaze melts and develops into a smooth glass-like layer while the ceramic body reaches a much more mature state.

After controlled cooling, the result is finished glazed ceramic ware.

11. Plain White and Solid-Color Tableware Follow a Simpler Route

Not every product needs underglaze artwork.

A plain white ceramic mug or solid glazed dinner plate may move directly from bisque preparation to glazing.

A typical route is:

Bisque inspection → cleaning → moisture conditioning if required → glazing → drying → foot wiping → glaze inspection → glaze firing → finished ware

This route is efficient for:

whiteware, solid-color collections and products where decoration will be added later.

12. Underglaze Decorated Tableware Uses a Different Route

For illustrated Christmas tableware, botanical dinnerware and other coordinated graphic collections, the underglaze route adds the decoration before the transparent glaze.

A typical sequence is:

Bisque inspection → cleaning → underglaze decal / printing / hand painting → drying → transparent glazing → drying → foot cleaning → glaze inspection → glaze firing → finished decorated ware

This production logic allows the artwork to become visually integrated beneath the glaze.

For a coordinated collection, the same design language can then be adapted across multiple forms—from dinner plates and bowls to mugs, tea sets and servingware.

13. In-Glaze and On-Glaze Decoration Are Different Processes

One common source of confusion in ceramic sourcing is the difference between underglaze, in-glaze and on-glaze decoration.

They are not interchangeable.

Underglaze

Decoration is applied before the transparent glaze.

Bisque → decoration → glaze → glaze firing

The image remains beneath the finished glaze layer.

In-Glaze

The ceramic product is first glaze-fired.

A compatible decoration is then applied and fired at a sufficiently high decoration temperature so the pigment interacts strongly with the glaze layer.

The exact terminology and firing conditions can vary between factories and decoration systems, so buyers should confirm the actual process rather than relying only on the label “in-glaze.”

On-Glaze

The product is already fully glaze-fired before the design is added.

Decals or other decoration are applied to the glazed surface and then fired again at a lower decoration temperature.

For many decal systems, this additional firing may be around 750–820°C, although actual temperatures depend on the decoration system.

Because the decoration remains at or near the glaze surface, durability can differ from underglaze or suitable in-glaze systems.

For export food-contact ware, decoration composition and migration performance—including relevant lead and cadmium requirements—should be verified through product-specific testing for the destination market.

14. Common Defects During Underglaze Decoration and Glazing

Quality control at this stage focuses heavily on surface cleanliness, moisture, glaze condition and decoration adhesion.

Crawling

The glaze pulls away from areas of the ceramic surface during firing, leaving exposed body.

Possible contributors include:

surface dust, contamination, poor glaze adhesion or unsuitable application conditions.

Pinholes

Small holes remain in the fired glaze surface.

These may be related to moisture, trapped gases, glaze bubbles, body decomposition or firing conditions.

Glaze Running

The molten glaze moves excessively during firing.

Possible causes include excessive glaze thickness, unsuitable glaze properties or firing conditions.

Incomplete Decoration

A decal or printed design may become damaged, displaced or incomplete.

The issue can originate from incorrect application, trapped water or air, insufficient drying, surface condition or incompatibility between the decoration and firing system.

Bare or Thin Glaze Areas

Some areas fail to receive enough glaze.

This can result from incomplete dipping or spraying, poor body wetting or inconsistent application.

Identifying these issues before final firing helps reduce unnecessary loss later in production.

Why This Stage Matters to Ceramic Buyers

For importers, retailers and brands, decoration and glazing are not simply aesthetic processes.

They affect:

appearance, surface feel, durability, cleanability, food-contact performance and consistency across production batches.

A buyer developing a ceramic collection should therefore discuss more than just artwork.

Important questions include:

Which decoration method is being used?

Is the design underglaze, in-glaze or on-glaze?

What glaze will cover or accompany the decoration?

How will curved surfaces be decorated?

Which areas contact food or beverages?

What market will the product enter?

What product-specific testing will be required?

These decisions should ideally be made during product development rather than after mass production begins.

From Artwork to a Coordinated Ceramic Collection

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

A project can begin with something as simple as a buyer's illustration, color palette or seasonal concept.

From there, the design can be developed across:

ceramic mugs, plates, bowls, cups and saucers, teapots, coffee ware, serving platters and coordinated tableware collections.

Customization may include:

decals and artwork adaptation, glaze colors, logo application, mold and shape development, decorative techniques, packaging development and private-label presentation.

The manufacturing route is then selected according to the product material, design, intended use and target market.

Talk to Us About Your Ceramic Tableware Idea

If you are developing a ceramic mug or dinnerware collection, share your ideas with us.

Tell us your preferred style, usage scenario, target market, brand or logo concept, product shapes, artwork direction and special decoration requirements.

Our team can support the project from sampling and ceramic body preparation through decoration, glazing, firing, quality control and bulk production.

Whether the goal is a minimalist white mug, an illustrated botanical dinnerware range, a Christmas collection or a fully customized private-label tableware program, the right manufacturing process starts with understanding how the design needs to perform—not only how it should look.

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