Spode Blue Italian Mug, Set of 4 4- 18-Ounce Mugs Made of beautifully white translucent Porcelain Rich blue chinese inspired pattern created with hand applied lithographs underglaze for vibrant color and durabilty on a porcelain white body Oven Safe to 340 degrees. Dishwasher Safe Microwave Safe Never place empty items in microwave or oven. Guaranteed against manufacturer defects