Which of the following is commonly used in making an enameled watch dial?

The choice of a metal support as commonly used in making an enameled watch dial is rooted in both functional and aesthetic considerations. Metal provides a strong and stable base for the enamel, which is a glass-like material that is applied in layers and then fired at high temperatures to create a durable and glossy finish.

Using a metal support not only enhances the structural integrity of the dial but also allows for intricate designs and quality craftsmanship, which are hallmarks of high-end watchmaking. The metal can also be treated or coated to achieve different colors and finishes, adding to the overall visual appeal of the watch.

In contrast, plastic lacks the durability and traditional aesthetic associated with fine watchmaking, glass might be used as an outer layer or cover but is not suitable as a base for enamel, and rubber does not provide the necessary support or finish that the enamel requires to adhere properly and look attractive.