Overglaze refers to the group of colors that are applied to a previously glazed and fired surface. These overglaze materials are then fired to a temperature considerably lower than the original glaze firing. Keep in mind that a satin or matte glaze will provide a satin or matte finish to the luster or metallic, and a gloss glaze will furnish the glossy finish more commonly associated with over glazes. In firing an overglaze, the glaze is softened to the point where the overglaze settles onto the surface and becomes a part of the surface. Overfiring will cause the colors to sink too deeply into the glaze, resulting in distortion, fade-out or burnout. Underfiring will prevent the glaze from becoming soft enough to receive the color, thus causing poor adherence. With proper firing, an overglaze decoration becomes a permanent part of the glaze and provides a durable, lasting finish that is not obtainable with any other decorating medium. Depending upon the glaze, fire between c/022-018.
Hazards: Not Food Safe. Ceramic overglaze materials may present a hazard through inhalation of dusts or fumes while being used and fired. Avoid prolonged contact. Keep out of reach of children. For additional protection against fumes, the use of a respirator is recommended.
