The general firing range for Thompson enamels is 1400°–1500°F (760°–815°C). Enamels will fuse in 1 to 4 minutes depending on the color, type and thickness of the metal, and the temperature of the kiln. A typical firing is 1450°F (790°C) for around 2 minutes. Enamel powders will change in color after firing. Refer to the color image for a general indication of the fired result. Computer monitors do not accurately represent color, and enamel colors may vary slightly from batch to batch, so pre-testing your enamels before using them is recommended. Bronze is not recommended for enameling. The enamels are not formulated to adhere to it and will crack or chip off. Lead Free / 80 Mesh It is advisable to pre-test enamel colors on examples of the workpieces you are using to resolve any slight variances that may occur on your specific metals. Additional firing notes: 2040 Hard Fusing Clear may have a slightly yellow tint when fired directly on silver. Initial firing on copper should be 1550°F (845°C) to clear the oxides off the metal. The copper should appear clean and bright under the enamel If it appears reddish or mottled it wasn't fired hot enough and/or long enough.