Underglaze can generally be fired twice, but there are considerations to keep in mind to ensure the best results.
The first firing is necessary to set the underglaze and bond it to the clay surface. This firing prepares the piece for subsequent glazing and additional firings.
If you plan to apply a glaze over the underglaze, a second firing is required to melt and fuse the glaze onto the clay surface.
Ensure that the underglaze and glaze are compatible in terms of firing temperature. Firing at the appropriate temperature is essential to prevent issues.
Be cautious not to overfire the underglaze, as this can affect its color and texture. Follow the manufacturer’s recommendations for firing temperatures.
Firing underglaze twice is a common practice when glazing ceramic pieces. Adhering to proper firing techniques and temperature guidelines will help you achieve successful results.