Underglaze is a versatile technique that adds vibrant color and intricate detail to ceramics before they’re glazed and fired. Unlike traditional glazes, underglazes allow us to paint precise designs that stay sharp and vivid after firing. Whether you’re a beginner or an experienced potter, mastering an underglaze recipe can elevate your work to a whole new level.
We love how underglazes give us the freedom to experiment with colors and textures without worrying about running or fading. Plus, they’re perfect for layering and creating unique effects that make each piece truly one-of-a-kind. In this recipe, we’ll guide you through making your own underglaze that’s easy to apply and delivers consistent, beautiful results every time.
Ingredients
To craft a reliable underglaze recipe, we need to gather precise ingredients that ensure vibrant color and smooth application. Each element plays a crucial role in texture, adhesion, and firing properties. Here’s a detailed list of the essential components:
- Kaolin (China clay) – 100 grams
Provides the underglaze with a smooth texture and improves adhesion to the ceramic surface. - Ball clay – 50 grams
Enhances plasticity and workability, helping the underglaze apply evenly. - Feldspar – 30 grams
Acts as a flux, lowering the firing temperature and helping the underglaze mature. - Silica (flint) – 40 grams
Adds durability and strength to the fired underglaze. - Colorants (oxides or stains) – 5 to 20 grams (depending on desired saturation)
Choose natural oxides like cobalt for blue, iron for red-browns, or commercial stains for brighter, consistent hues. - Water – Approximately 200 milliliters
Used to create a smooth slurry for easy brush or sponge application.
Underglaze Ingredient Table
| Ingredient | Quantity | Purpose |
|---|---|---|
| Kaolin | 100 grams | Smooth texture, adhesion |
| Ball Clay | 50 grams | Plasticity, workability |
| Feldspar | 30 grams | Flux, firing temperature reduction |
| Silica (Flint) | 40 grams | Durability, strength |
| Colorants (oxides/stains) | 5–20 grams | Color saturation and vibrancy |
| Water | ~200 milliliters | Slurry preparation for application |
“Precision in measuring these ingredients gives us consistent results and brilliant color retention after firing.”
By combining these ingredients with a proper mixing technique, we can achieve a balanced underglaze formula that applies smoothly, maintains detailed designs, and fires to a stable, durable finish.
Equipment Needed
To create a smooth and vibrant underglaze using our recipe, having the right equipment on hand is crucial. Each tool ensures precision, consistency, and ease throughout the mixing and application process.
Essential Tools for Preparing Underglaze
- Digital scale – For accurately weighing each ingredient to maintain the right balance in the formula.
- Mixing containers – Non-reactive buckets or bowls, preferably plastic or glass, to combine materials safely.
- Measuring spoons – Helpful for smaller amounts of colorants and additives.
- Electric mixer or drill with mixing attachment – To achieve a uniform and lump-free underglaze consistency quickly.
- Sifter or fine mesh sieve – To sift powders like silica and ball clay and avoid clumps.
- Rubber spatulas or stirring sticks – For scraping down sides and folding ingredients thoroughly.
- Plastic bottles or jars with lids – For storing the finished underglaze and maintaining freshness.
- Protective gloves and dust mask – To handle dry powders safely and avoid inhalation of fine particles.
Equipment Summary Table
| Equipment | Purpose |
|---|---|
| Digital scale | Precise measurement of ingredients |
| Mixing containers | Safe combination of powders and liquids |
| Measuring spoons | Accurate dosing of small quantities |
| Electric mixer | Homogeneous blending without clumps |
| Sifter/fine mesh sieve | Clump removal from dry ingredients |
| Rubber spatulas | Thorough scraping and stirring |
| Storage containers | Preserving underglaze quality |
| Gloves and dust mask | Safety during powder handling |
Using this equipment ensures that our underglaze recipe comes together perfectly every time, allowing us to focus on creating vibrant and detailed ceramic designs without interruption. Remember, precision in preparation transfers directly to brilliance in firing results.
Preparing the Underglaze
To achieve a smooth and vibrant underglaze, precise preparation is essential. In this section, we will walk through the step-by-step process to mix the base and incorporate colorants, ensuring consistent texture and stunning results.
Mixing the Base
First, we focus on creating the foundation of the underglaze by combining the key dry ingredients with water. Follow these steps for optimal consistency:
- Measure Ingredients Accurately
Using a digital scale, weigh the following powders precisely according to the recipe: kaolin, ball clay, feldspar, and silica.
- Combine Dry Ingredients
Sift all dry components together in a non-reactive container to remove clumps and ensure uniformity. This creates a fine blend for smooth application.
- Add Water Gradually
Pour filtered water slowly while stirring with a rubber spatula or use an electric mixer on low speed. This prevents lumps and produces a creamy, paint-like consistency.
- Mix Thoroughly
Blend the mixture for at least 5 minutes to achieve a fully homogenized base with no dry or watery spots. Scrape down the sides of the bowl as needed to incorporate all material.
- Test Consistency
The underglaze should flow easily but not be watery—similar to heavy cream. Adjust water or dry mix accordingly.
| Ingredient | Role | Measurement (Example) |
|---|---|---|
| Kaolin | Improves adhesion and texture | 50 grams |
| Ball Clay | Adds plasticity and smoothness | 30 grams |
| Feldspar | Acts as a flux for durability | 15 grams |
| Silica | Provides structure and hardness | 10 grams |
| Water | Controls consistency | 100 ml (approx.) |
Tip: Use a sifter again after mixing if any lumps persist before adding colorants.
Adding Colorants
Once the base is perfectly mixed, it’s time to infuse your underglaze with vivid hues using colorants. Follow these expert steps to maintain brightness and stability:
- Choose Your Colorants
Select compatible oxide or commercial ceramic stains that fire well within your kiln range.
- Pre-Dilute Colorants
Mix pigments in a small amount of water to form a smooth slurry. This prevents clumping when added to the underglaze base.
- Incorporate Gradually
Add the diluted colorants in small increments. Use the electric mixer on low to blend each addition evenly.
- Check Color Intensity
Apply a small test stroke on a ceramic test tile and fire it to preview results. Adjust pigment concentration as needed for desired vibrancy.
- Store Properly
Transfer colored underglaze into airtight containers labeled by color. Shake or stir before each use to keep pigments dispersed.
| Colorant Type | Common Usage | Typical Amount per 100g Base |
|---|---|---|
| Cobalt Oxide | Deep blues | 1-2 grams |
| Iron Oxide | Reds, browns, blacks | 1-3 grams |
| Chrome Oxide | Greens | 1-2 grams |
| Commercial Stains | Wide color range | 2-5 grams |
“Always handle dry colorants with gloves and a mask for safety.“
We recommend testing small batches when mixing new colors to assure consistency and vibrancy after firing. This approach ensures your underglaze stays stunning and durable on each ceramic piece.
Applying the Underglaze
Applying underglaze correctly is crucial to achieving vibrant colors and sharp, lasting designs on our ceramics. Let’s explore how to prepare surfaces and use techniques that ensure an even, flawless finish every time.
Surface Preparation
Before applying underglaze, we must focus on surface preparation to guarantee optimal adhesion and color clarity. Follow these essential steps:
- Clean the Surface: Remove all dust, grease, and residue using a damp sponge or cloth. A clean surface prevents imperfections.
- Leather-hard Clay: Apply underglaze to clay that is leather-hard or slightly dry but still porous. This enhances pigment absorption and bonding.
- Smooth the Surface: If the clay surface is rough, gently smooth it with a damp sponge to avoid uneven underglaze application.
- Avoid Contaminants: Use gloves to handle ceramics and keep oils or dirt from disrupting the underglaze finish.
Tip: Test your prepared surface by brushing a small amount of underglaze on a hidden spot to check absorption and adherence.
Techniques for Even Application
Achieving a consistent and smooth layer of underglaze involves mastering a few key techniques. These methods help us prevent streaks, blotches, and uneven color coverage:
| Technique | Description | Tips |
|---|---|---|
| Brush Application | Use soft, synthetic brushes in multiple thin coats. Allow each coat to dry slightly before applying the next. | Avoid heavy strokes to minimize brush marks. |
| Sponge Dabbing | Dab with a natural sponge for textured or gradient effects. Works well for subtle color depth. | Use a light touch and build gradually for best results. |
| Spraying | Use a spray gun or airbrush for ultra-smooth and even coats, especially on curved surfaces. | Thin the underglaze properly to avoid clogging and drips. |
| Slip Trailing | Apply underglaze with a squeeze bottle or fine nozzle to create precise lines and dots. | Practice steady hand movements to maintain control. |
Step-by-step Brush Application:
- Load your brush lightly with the underglaze.
- Apply a thin even coat in one direction.
- Let dry for 10-15 minutes or until tacky.
- Apply a second coat perpendicular to the first for full coverage.
- Avoid applying thick layers to prevent cracking or peeling during firing.
“Consistency is key” — a smooth, even coat ensures vibrant color retention and sharpness after firing.
Using these preparation and application techniques helps us maximize the beautiful effects of our underglaze recipe and deliver stunning, durable ceramic art.
Firing and Finishing
Once we have applied the underglaze to our pieces, the next crucial steps are drying and firing. Proper drying ensures the underglaze sets correctly while firing locks in vibrant colors and durability. Let’s explore the critical factors that affect these final stages.
Drying Time
Allowing the underglaze to dry completely before firing is essential to prevent cracking or bubbling. We recommend these drying guidelines:
- Ambient drying: Let pieces air dry at room temperature for at least 24 hours.
- Controlled drying: Avoid rapid drying or direct sunlight as it can cause uneven shrinking.
- Check dryness: The surface should feel bone dry with no tackiness before moving to the kiln.
“Patience during drying preserves the integrity of your colors and designs.“
| Drying Step | Recommended Time | Key Notes |
|---|---|---|
| Initial air drying | 24 hours | Keep away from heat sources and drafts |
| Additional curing | 12–18 hours | For thicker or heavily layered pieces |
| Final dryness check | Before firing | Surface must be completely dry |
Kiln Temperature and Duration
Firing temperature and duration directly impact the underglaze’s final color brightness, adhesion, and surface finish. Following these firing parameters yields consistent results:
| Stage | Temperature Range (°F) | Duration | Purpose |
|---|---|---|---|
| Bisque firing | 1700–1900 | 8–12 hours | Hardens clay body before glazing |
| Glaze firing | 2100–2300 | 10–14 hours | Seals underglaze with glaze coat |
- Fire your bisque ware first to a temperature that safely hardens the clay without fluxing the underglaze.
- When applying clear glaze over the underglaze, maintain firing temperature in the cone 06 to cone 04 range (approximately 2100°F to 2300°F).
- Avoid firing above recommended temperatures to prevent color fading or glaze defects.
- Use a slow firing ramp during temperature increases to protect detailed artwork.
“Firing is the final step where heat transforms our underglaze from matte paint to durable, vibrant ceramic art.“
By carefully controlling drying and firing, we ensure our underglaze recipes deliver bright, lasting results that stand the test of time.
Tips for Best Results
To achieve the brightest, sharpest, and most durable effects with our underglaze recipe, we must follow these essential tips precisely. Proper technique and attention to detail ensure vibrant color and lasting adhesion on ceramic pieces.
Prepare the Surface Thoroughly
- Always work on leather-hard clay where the surface is firm yet slightly moist. This ensures optimal underglaze adhesion.
- If the surface is too dry or too wet, underglaze may not bond well, causing flaking or uneven color.
- Gently wipe dust or debris from the surface before application for a smooth finish.
Apply Thin, Even Coats
- Use a soft-haired brush or appropriate tool to apply thin layers of underglaze. Thick coats may cause cracking or uneven firing effects.
- Allow each coat to dry completely (about 10-15 minutes) before applying the next.
- Multiple thin layers build up richer color without compromising surface integrity.
Drying Guidelines
- Let the underglazed piece dry at room temperature for at least 24 hours, avoiding direct sunlight or drafts.
- Rapid drying increases risk of cracks and bubbling.
- For added control, cover the piece loosely with plastic and remove after 12 hours to slow moisture loss gradually.
Firing Parameters
- Bisque firing temperature: 1828–1940°F (998–1060°C)
- Glaze firing temperature: 2165–2232°F (1185–1222°C) depending on the glaze used
- Controlled heating and cooling rates prevent damage to underglaze layers.
| Firing Stage | Temperature Range (°F) | Temperature Range (°C) | Purpose |
|---|---|---|---|
| Bisque Firing | 1828–1940 | 998–1060 | Hardening clay for glazing |
| Glaze Firing | 2165–2232 | 1185–1222 | Melting glaze and sealing |
Safety & Handling
- Always wear protective gloves and a dust mask when mixing or applying underglazes with powdered colorants to avoid inhalation or skin irritation.
- Keep work area well-ventilated.
- Clean tools immediately after use to prevent dried residue buildup.
Testing Small Batches
- We recommend testing every new batch of underglaze on sample tiles before full application. This step helps us check for:
- Color consistency after firing
- Application smoothness
- Adhesion and surface finish
“Perfecting our underglaze application means respecting each stage from preparation to firing. A slow methodical approach protects the brilliance and integrity of our ceramic artwork.”
By integrating these tips into our process, we maximize the quality and vibrancy of our underglaze decorations and ensure professional results every time.
Troubleshooting Common Issues
When working with underglaze, certain challenges can arise that affect the final appearance and durability of our ceramic pieces. Here, we address some frequent problems along with clear solutions to ensure our underglaze recipe delivers consistent, professional results.
Issue 1: Cracking or Crazing After Firing
Cracking or crazing occurs when the underglaze layer contracts too much during drying or firing. This leads to visible cracks on the surface that compromise the design quality.
How to fix:
- Ensure even, slow drying at room temperature for at least 24 hours to avoid rapid shrinkage.
- Avoid applying thick coats of underglaze; use thin, even layers for better flexibility.
- Double-check the balance of clay additives in the recipe to match the clay body’s thermal expansion.
- Adjust the firing schedule to include a soak stage at peak temperature, relieving internal stresses.
Issue 2: Faded or Dull Colors Post Firing
Sometimes colors appear muted rather than vibrant after firing because of incorrect firing temperature or glaze compatibility issues.
How to fix:
- Follow firing guidelines carefully: bisque fire at cone 06-04 and glaze fire at cone 5-6 for optimal color brightness.
- Test underglaze with your specific glaze to ensure color integrity is maintained.
- Confirm that the underglaze is fully dry before glazing to prevent color washout.
- Avoid overfiring which can cause colors to dull or melt into the base glaze.
Issue 3: Poor Adhesion or Flaking Underglaze
If the underglaze flakes off during handling or firing it usually indicates inadequate surface preparation or incorrect underglaze consistency.
How to fix:
- Always apply underglaze on clean, leather-hard clay surfaces free of dust and oils.
- Mix the underglaze evenly to avoid settling and separation; maintain the right viscosity similar to heavy cream.
- Use primers or slip layers on very dry clay to enhance adhesion.
- Store mixed underglaze in airtight containers and stir well before use.
Issue 4: Bubbling or Blistering During Firing
Bubbles or blisters form when trapped moisture or air expands rapidly in the kiln leading to uneven surfaces.
How to fix:
- Allow ample drying time to expel moisture completely before firing.
- Apply underglaze in thin, even coats to minimize trapped air pockets.
- Use a proper degassing firing schedule, including slow ramp-up phases to gradually remove moisture.
- Avoid overly thick glaze overlays that can trap air underneath.
Troubleshooting Guide Table
| Problem | Possible Cause | Recommended Action |
|---|---|---|
| Cracking or Crazing | Rapid drying, thick layers | Slow ambient drying, thin even coats |
| Faded Colors | Overfiring, glaze incompatibility | Correct firing temp, test glaze compatibility |
| Poor Adhesion | Dusty surface, thick slurry | Clean surface, adjust underglaze consistency |
| Bubbling/Blistering | Trapped moisture or air | Thorough drying, slow firing ramp |
“Precise control of the drying and firing process is essential to maximize the potential of our underglaze recipe and prevent these common issues.”* Adhering closely to these steps helps us create vibrant, sharp, and durable ceramic pieces every time.
Conclusion
Mastering underglaze opens up a world of creative possibilities in ceramics. With the right recipe, tools, and techniques, we can achieve vibrant colors and sharp details that stand the test of firing. Paying close attention to preparation, application, drying, and firing ensures our pieces not only look stunning but also maintain their quality over time.
By testing small batches and troubleshooting common issues, we refine our process and gain confidence in our results. Underglaze is more than just a decorative step—it’s a crucial part of bringing our ceramic art to life with lasting impact.
Frequently Asked Questions
What is underglaze in ceramics?
Underglaze is a colored decoration applied to ceramic pieces before glazing and firing. It allows for vibrant colors and detailed designs that remain sharp and clear after firing.
How does underglaze differ from traditional glaze?
Unlike traditional glazes, underglazes offer precise, intricate designs with vibrant colors that do not run or blur after firing, making them ideal for detailed artwork.
What are the key ingredients for making underglaze?
Essential ingredients include kaolin, ball clay, feldspar, silica, colorants, and water, each contributing to color vibrancy, smooth application, and durability after firing.
What tools do I need to make underglaze?
You need a digital scale, non-reactive mixing containers, measuring spoons, an electric mixer, a sifter, rubber spatulas, and storage containers, along with safety gear like gloves and a dust mask.
How do I prepare underglaze for use?
Mix the base ingredients thoroughly, then add colorants. Use an electric mixer for even consistency and sift the mixture to ensure smoothness before application.
What is the best way to apply underglaze?
Apply thin, even coats on leather-hard clay using a brush, sponge, spray, or slip trailing. Preparation of the surface is crucial for optimal adhesion and color clarity.
How should I dry underglaze before firing?
Dry underglaze slowly at room temperature for at least 24 hours to prevent cracks or bubbles. Avoid rapid changes in temperature to ensure an even finish.
What firing temperatures are ideal for underglaze?
Bisque firing usually ranges from 1800°F to 1940°F (982°C to 1060°C), followed by glaze firing at around 2230°F to 2345°F (1220°C to 1285°C) for best color and durability.
How can I achieve the best results with underglaze?
Prepare the surface well, apply thin coats evenly, follow precise drying and firing steps, and always test small batches first to ensure color consistency and adhesion.
What common problems occur with underglaze and how do I fix them?
Issues like cracking, fading, poor adhesion, and bubbling are often caused by improper drying, firing temperatures, or surface prep. Slow drying and proper firing can prevent these problems.