Glaze Colorant Calculator
Glaze
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Glaze Colorant Calculator
Calculate oxide and stain additions to produce a target color in a glaze batch.
Reviewed by ClayCalc Editorial · Updated
Results
Enter your measurements above and click Calculate.
Colorant Percentage Ranges
Glaze colorants are metal oxides or carbonates added as a percentage of the total dry glaze weight. The percentage determines not just intensity but can change the color completely (iron oxide moves from amber at 2% to deep tenmoku brown-black at 10%). The ranges shown are starting points — test tiles are always required.
Common Colorants at a Glance
| Colorant | Color | Typical Range | Notes |
|---|---|---|---|
| Cobalt Carbonate | Blue | 0.25–1% | Very potent — start at 0.25% |
| Red Iron Oxide | Amber → Brown → Red | 2–12% | Reduction: celadon at 1–2% |
| Copper Carbonate | Green / Turquoise | 1–5% | Reduction: copper reds |
| Manganese Dioxide | Purple / Brown | 2–8% | Limit to <5% for food ware |
| Chrome Oxide | Olive Green | 0.5–3% | Never near tin glazes |
Atmosphere Effects
Firing atmosphere (oxidation vs. reduction) dramatically changes colorant results. Copper carbonate produces teal-green in oxidation but can create stunning copper reds in reduction. Iron oxide produces warm ambers and browns in oxidation but cool celadons and carbon-trap effects in reduction. These ranges apply to oxidation firing; adjust expectations for alternative atmospheres.
Method & review note
About this calculation
Performs recipe and slurry arithmetic. A calculated percentage or expansion estimate cannot establish glaze durability, fit, toxicity, or food-contact suitability.
Reference: Digitalfire — Ceramic Glaze. See the editorial methodology for testing, precision and corrections.
Input handling: Values are sent to the ClayCalc server for this request and are not written to the application database.