The design of the Panerai watch’s dial uses a sandwich sandwich structure. This design was originally developed for functional considerations to ensure that Navy commandos can be clearly read even in low light conditions: time. The sandwich sandwich structure is an innovative design of conventional construction, which can place luminous materials in the grooves in the dial. The dial with sandwich structure is composed of two overlapping discs. A large amount of luminous material is placed on the lower disc, and its light is transmitted from the corresponding hollow hour mark and number on the upper disc. In this way, a large amount of luminous material produces a large amount of light, which can be revealed through this design, showing the maximum degree of readability.