Plique a jour is a French word meaning letting the daylight in. It is an art of enamelling and using enamelling process to allow light to pass through the translucent object. In this process, thin metal lines are filled with enamel and heated and produces a version of stained glass. The process of making such glass is similar to cloisonné but it makes a little difference in its amount of transparency. Some plique a jour products are also made n Chine.