What is the primary composition of enamel used in precious metalwork?

The primary composition of enamel used in precious metalwork is a powder or paste that becomes glasslike when heated. Enamel typically consists of finely ground glass mixed with various oxides that impart color. When heated to high temperatures, this mixture melts and fuses to the surface of the metal, creating a durable, glassy coating. This glasslike finish is not only visually appealing but also adds protection to the underlying metal.

In contrast, the other options do not accurately describe how enamel is utilized in metalwork. For example, a thick paste that dries quickly would not connote the transformative heating process that is central to enameling. Similarly, while some materials can be layered, true enamel requires the application of heat to achieve its final glassy state rather than being a fluid additive. Furthermore, a paint that can be used without heat suggests a different type of product that does not produce the same desired effects as heated enamel.