This set of 4 mugs is made of bone china. They are dishwasher and microwave safe and come in a beautiful gift box. Each mug is approximately 11 oz. Robert Bateman's realistic painting style, featuring wildlife in its habitat, encourages the viewer to closely observe the natural world. Besides being one of Canada's best-known artists, he is a naturalist, recognized by the Audubon Society as one of the 20th century's heroes of conservation. He is a spokesman for many environmental and preservation issues, using his art to raise millions of dollars for these causes.