The beauty and creativity of textured ceramics gives the artist an unparalleled opportunity to make a stunning creation. It is therefore an important step to protect this piece of art with a durable coating of glaze. This final step acts as a protector because glaze is made with sand that turns into glass when it is fired in a kiln at the proper temperature. It ensures the piece has a longer life, with brilliant colors and a glassy shine. If shine is not needed, there are glazes that become a smooth matte finish when fired at the proper temperature. It is up to the artist to choose matte or glossy glaze for the final step.
The glass of glaze comes from the pure sand that is used in mixing the glaze. When fired in a kiln, this sand melts into a strong glass coating. It bonds with the underlying ceramic piece and forms a tough surface over the piece. It adheres strongly and reflects light according to the type of finish the glaze produces. A glossy finish reflects light at a steep angle and makes the piece appear very shiny. Each particle of light is reflected in one direction at a time. This gives the glossy glazed piece the look of a mirror. This finish is smooth to the touch.
A matte finish glaze uses larger sand particles than a glossy finish glaze. It almost seems a contradiction that this type of finish would feel smooth once fired, but that is the case with this type of glaze. The larger particles melt and form glass in the same way a glossy finish is formed. They also form a layer that bonds directly with the ceramic piece and a tough outer coating for protection.
Matte finishes are smooth because the sand particles melt into glass, and the smoothness of the glaze is not affected by the light reflecting properties. This glass glaze diffuses light rather than concentrating it when it is reflected because there are microscopic bumps in the inner material of the glaze. Scattering the light means there is not a mirror-like finish on the piece. It still has the protective properties of the glossy glaze and simply reflects light in a scattered pattern for less shine.