The "underglaze" decoration technique consists of applying colors or pigments to a piece before it is covered with a glaze. Underglaze colors are applied to the piece in a raw or bisque state, that is, before the final glaze has been applied or before the piece is fired. This technique is widely used in decorative ceramics, as it allows the colors to fuse with the glaze during the firing process, which not only protects them, but also gives them a glossy and durable finish. Unlike glazes applied over a fired ceramic layer, underglaze colors are more deeply integrated with the piece, creating a more uniform appearance with a vitreous appearance after firing.
In some cases, pigments are mixed with a gum, such as arabic gum, to help fix the colors to the ceramic surface prior to glaze application. This fixative ensures that the pigments do not slip or mix with the glaze when applied, thus maintaining the definition and precision of the design.
The underglaze technique also allows the creation of detailed and complex designs, as the pigments can be applied with precision before the final firing. One of the most famous applications of the underglaze technique is seen in traditional Delft pottery. In this technique, blue-on-white patterns are applied using blue pigments under a layer of transparent glaze, creating the distinctive style of Delft pottery.
Interesting Fact
Underglaze pigments become part of the glaze during firing, making them wear-resistant and suitable for tableware and everyday objects.
Helpful Tip
For best results, apply undercoat pigments evenly and make sure they are completely dry before applying the glaze.
