Since copper is a pure metal, it oxidises on exposure to the atmosphere. The lacquer coat retards the oxidation and helps retain the shop-sheen of the copper product. In time, your lacquered products may darken and begin to acquire a patina. To clean, wipe with a dry or soft moist cloth. Never wash your lacquered products. Serving dry foods on a lacquered copper product is safe, but always line the product with banana leaves or a doily or a muslin cloth while serving moist food. Never serve or store wet food in a copper product. You can however float tea-lights and flowers in your copper floaters, as water will not harm the lacquer finish. Change the water in your floater daily and wipe dry before the next use.