Underglaze and overglaze decoration techniques are two distinct methods used in ceramics to create stunning designs, but they differ significantly in application, firing, and final appearance.

Underglaze Decoration involves applying pigments or designs directly onto the raw or bisque-fired clay before the final glaze is added. The colors are then sealed beneath a transparent glaze during the high-temperature firing process (typically 1200-1300°C). This technique produces durable, fade-resistant designs with a matte or semi-matte finish. Common underglaze materials include oxides and stains mixed with a flux to bond with the clay.

Overglaze Decoration, also known as on-glaze or enamel decoration, is applied after the final glaze firing. Artists use low-fire pigments (often metallic oxides or enamels) that melt at lower temperatures (700-900°C) in a secondary firing. This method allows for vibrant, detailed designs but is less durable than underglaze, as the pigments sit on the glaze surface and can wear over time.

Key differences include:

1. Application Timing: Underglaze is applied before glazing, while overglaze is added after.

2. Firing Process: Underglaze requires high-fire temperatures, whereas overglaze uses low-fire.

3. Durability: Underglaze designs are more resistant to wear and fading.

4. Visual Effects: Overglaze offers brighter, glossier finishes, while underglaze appears more subdued.

Choosing between these techniques depends on the desired aesthetic, functional requirements, and firing capabilities. Both methods continue to inspire ceramic artists worldwide.