Luster glaze was meant to resemble copper, silver, or gold. The term luster includes any piece with some luster trim. It has been used since the sixteenth century. Some of the luster found today was made during the nineteenth century. The metallic glazes are applied on pottery. The finished color depends on the combination of the clay color and the glaze. Blue, orange, gold, and pearlized luster decorations were used by Japanese and German firms in the early 1900s. Early luster pieces had the same glaze on the inside as they did on the outside. Tea Leaf pieces have their own category.