Copper-free mirrors, also known as environmentally friendly silver mirrors, refer to silver mirrors that do not contain copper. During the production process of ordinary silver mirrors, a layer of copper is plated after the reflective layer of silver is plated to protect the silver layer to prevent the silver from being exposed to the air and oxidized and darkened. During the production process of copper-free mirrors, palladium chloride is used instead of copper, thus avoiding the problem of copper pollution to the environment.