Final answer:
The application of a slip made red and black figure pottery turn black when exposed to oxygen when fired.
Step-by-step explanation:
Black-figure pottery and red-figure pottery are two distinct ancient Greek pottery styles. In black-figure pottery, the figures and designs were painted with a mixture of slip (a clay and water mixture) and iron-rich clay. When fired, the iron-rich clay turned black when exposed to oxygen. Red-figure pottery, on the other hand, used a technique of painting the background black and leaving the figures in the natural color of the clay. This was achieved by applying a slip made from finely ground clay minerals, such as kaolin, to the areas that were intended to stay red.
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