Underglaze can be applied to clay at different stages of its drying process, depending on the desired effect and the specific technique you intend to use.
One common stage for applying underglaze is when the clay has reached the leather-hard stage. At this point, the clay is still somewhat pliable but has lost much of its moisture, making it less prone to distortion when underglaze is applied.
Underglaze can also be applied to bone-dry clay. This stage offers a more absorbent surface, allowing the underglaze to be absorbed into the clay and creating a different visual effect.
Applying underglaze to greenware (unfired clay) is possible but requires more careful handling to prevent damage to the delicate surface.
The stage at which you apply underglaze will influence the final appearance of your piece. Experimenting with different stages can lead to unique results and allow you to explore various textures and effects.
Underglaze can be applied at different stages of clay, each offering its own artistic opportunities and challenges. Choose the stage that best suits your intended outcome and artistic vision.