Creating Custom Colors: Testing Your Own Colorants with Five Glaze
Hey there! It's Ella, and I'm excited to share one of my favorite aspects of working with Five Glaze - the freedom to create your own custom colors. While our tested colorant combinations give you reliable, beautiful results right out of the box, there's something magical about developing a palette that's your own.
Today we're diving into the world of custom colorant testing. This is where science meets art, and a little bit of math helps you achieve that perfect shade.
Why Test in Small Batches First?
Before we jump into the how-to, let's talk about why we always recommend testing colorants in 100 grams samples before committing to a full gallon. It's all about smart experimentation.
Save Materials: Testing small means you're not wasting expensive colorants or base glaze if something doesn't work out.
Learn Faster: You can test multiple ratios and colors simultaneously, building your knowledge library quickly.
Avoid Disasters: Some colorants can cause surface defects like bubbling, pinholing, or crawling at higher percentages. Better to discover this on a test tile than on your favorite piece!
Perfect Your Recipe: Once you nail down the perfect percentage in your test, you can scale up with complete confidence.
Supply List for Custom Colorant Testing
Having the right supplies makes testing much easier and more organized.
Essential Supplies:
- Digital scale (accurate to 0.1 grams)
- Small containers for dry mixing (deli containers work perfectly!)
- Measuring spoons or small scoops
- Labels and permanent markers
- Small whisk or mixing tool
- Your chosen colorants
- Five Glaze base powder
Highly Recommended:
- Small sieve (80-mesh works great for small batches)
- Test tiles or small bisque pieces
- Notebook for recording recipes and results
- 100 ml graduated cylinder for water measurement
For Line Testing:
- Multiple identical test tiles
- Wax resist or tape for creating sections
- Small brushes for application
Base Glaze Versus Full Formula
Here’s a key concept:
-
Base glaze = the glaze recipe without any colorants (e.g., Serotonin).
-
Full formula glaze = base glaze plus colorant(s).
Colorants are just pigments—they aren’t glazes by themselves.
Weighing Out the Base Glaze
For a 100 grams test, start by weighing exactly 100 grams of dry base glaze (e.g., Serotonin) into your container. If you’re testing multiple colorants, repeat so each container starts with 100 grams of base glaze—not a mix of base and colorant.
Understanding Colorant Percentages
When we say “3% colorant” or “5% colorant,” we mean a percentage of the base glaze weight—not the total mix. Your base glaze is always 100%, and the colorant is added on top. That’s why your final batch will weigh more than 100 grams.
Most ceramic colorants work best between 0.10% and 10% of the base glaze weight, with 5% being a great place to start.
Lower Percentages (3-5%):
- Subtle, soft colors
- Good for pastels and earth tones
- Less risk of surface defects
Medium Percentages (5-7%):
- Rich, saturated colors
- The sweet spot for most colorants
- Good balance of color and surface quality
Higher Percentages (7-10%):
- Deep, intense colors
- Higher risk of bubbling or off-gassing
- Some colorants (like certain red mason stains) may cause surface issues
Important Note: Red mason stains and some other intense colorants are notorious for causing problems at high percentages. Always start conservatively with these!
The Math: Calculating Your Colorant
Don't worry - the math is simpler than it looks! Here's how to calculate colorant amounts for your 100 grams test samples:
Basic Formula:
Colorant Weight = (Desired Percentage ÷ 100) × 100 grams
Examples:
- 3% colorant: (3 ÷ 100) × 100 = 3 grams colorant + 100 grams base glaze
- 5% colorant: (5 ÷ 100) × 100 = 5 grams colorant + 100 grams base glaze
- 8% colorant: (8 ÷ 100) × 100 = 8 grams colorant + 100 grams base glaze
Adding Water
We recommend starting with 90% hydration:
Water weight= (90 ÷ 100) x base glaze weight (grams)
For 100 grams of base glaze, that's 90 grams of water.
Note: Water is based on the base glaze weight only, not the base glaze + colorant (or full formula).
Example: 5% Colorant Test
- Weigh out 100 grams of your dry Five Glaze base
- Add base glaze into a container
- Label container with colorant name and colorant percentage (e.g, Red Iron Oxide 5%)
- Weigh out 5 grams of your chosen colorant (e.g., Red Iron Oxide)
- Add colorant into properly labeled container
- Hydrate with 90 grams of water (90% hydration - our recommended starting point for most glazes)
- Mix the materials thoroughly after adding water
- Adjust water as needed based on consistency and specific gravity testing
Line Testing: Your Secret Weapon
Want to test multiple percentages at once? Line testing is your best friend! This technique lets you see how a colorant behaves across different percentages in a single firing.
Setting Up a Line Test:
- Choose Your Range: Let's say 3%, 5%, 7%, and 9%
- Make Multiple 100 grams Batches: One for each percentage
- Apply to Test Tiles: Use the same base clay and firing conditions
- Label Everything: Trust me—labels save you from mix-ups later!
- Fire Together: Same kiln, same firing schedule
Reading Your Results:
- Look for the percentage that gives you the color you want
- Check for surface defects like bubbling, crawling, pinholing, or texture changes
- Compare the surface finish to your base glaze without colorant - note any changes from glossy to matte, or other finish alterations
- Note any color shifts or unexpected reactions
Tip: Choose the lowest percentage that gives you the desired color effect - colorants are expensive, so being economical saves money!
Scaling Up to a Full Batch
The Calculation:
Desired Batch Size = (Test Percentage ÷ 100) × Desired Batch Size Weight (grams)
For a Standard Five Glaze Batch:
- Your Five Glaze bag contains 2,250 grams of dry base glaze
- For 5% colorant: (5 ÷ 100) × 2,250 = 112.5 grams of colorant
Practical Scaling Steps:
- Calculate your colorant amount using the formula above
- Follow standard hydration process: Use the same water ratio as your successful test (90% = 2,040 grams water for the full batch)
Troubleshooting Common Issues
Bubbling, Pinholing, or Rough Surface: Your colorant percentage might be too high. Drop the colorant percentage by 1-2% and retest.
Color Too Light: Increase the percentage gradually. Some colorants need higher percentages to show their true color.
Uneven Color Distribution: Make sure you're mixing the dry colorant and base thoroughly before dipping test tile.
Color Looks Different Than Expected: Some colorants are very sensitive to your clay body and firing atmosphere. This is normal - just adjust accordingly.
Finish Changes When You Expected to Match the Base: Some colorants can change the surface texture from what your base glaze normally produces. Compare your test to the base glaze without colorant to see what's changed, then decide if you like the new finish or need to adjust the percentage.
Pro Tips
Keep Detailed Records: Write down everything - colorant type, percentage, firing schedule, clay body. Future you will thank present you!
Test on Your Actual Clay: Different clay bodies can dramatically affect how colors develop.
Consider Your Firing: Oxidation vs. reduction, firing temperature, and cooling schedule all affect color development.
Start Conservative: It's easier to add more colorant than to fix an oversaturated batch.
Mix Colorants: Don't be afraid to blend different colorants for unique effects. Just remember to calculate percentages for the total colorant mixture.
Safety Considerations
When working with colorants, follow the same safety protocols as hydrating your base glaze:
- Wear appropriate PPE (dust mask, gloves, safety glasses)
- Work in well-ventilated areas
- Add powders to water, not the reverse (ensures that chemicals are properly hydrated)
- Keep detailed records of what you're using
Building Your Custom Color Library
Each successful test becomes part of your personal glaze library. I recommend keeping a notebook or digital file with:
- Colorant type and supplier
- Percentage used
- Photos of fired results
- Notes about surface quality and color development
- Clay body and firing details
Over time, you'll build an amazing collection of proven recipes that are uniquely yours.
Ready to Start Experimenting?
Custom colorant testing is one of the most rewarding aspects of working with Five Glaze. Yes, it requires a bit more planning and math than using our pre-tested combinations, but the creative possibilities are endless.
Start with one colorant that excites you, make a simple line test, and see what happens. You might discover your new signature glaze! Remember, every professional potter started with their first test tile - this is where your unique artistic voice begins to emerge.
The beauty of Five Glaze is that you have that perfect base to work from. Our bases are formulated to be stable and predictable, giving you the confidence to experiment knowing you're starting from a solid foundation.
Ready to dive into custom colors? Have questions about calculating percentages or interpreting your test results? I'd love to help you troubleshoot and celebrate your successes!