Bisque firing refers to the initial kiln firing cycle for greenware or unfired pottery to convert clay into a permanent, usable ceramic material. It prepares the clay for subsequent glazing and decoration prior to a final glaze firing.
What happens during bisque firing? Why is bisque firing essential? Let’s examine the bisque process from start to finish:
Most clay bodies are bisque fired between Cone 08-04, equating to about 1650-1945°F. Firing to higher temperatures risks over-firing the clay before glazing. Typical bisque temperatures for common clays:
The exact cone you choose within this range depends on the clay type and desired properties. Higher bisque temperatures make clay denser and less porous.
As clay heats in the kiln, several key changes occur:
The result is permanent, bisqueware ceramic. Bisqueware has an absorption rate of 10% or less, meaning it has achieved near zero porosity.
There are several advantages to bisque firing clay pieces before applying glazes and decoration:
Bisque firing is a stage you always want to take advantage of!
Follow these tips for successful kiln bisque firing:
Proper bisque firing prepares your clay work for vivid glazing outcomes. Be patient and let the bisque process run its full course.