When did black-figure and red-figure ceramics appear and how did they differ?

In the 6th century BC. vase painters applied drawings to vases with specially prepared black varnish. The background for these images was the natural reddish color of earthen vessels. Such vases are called black-figure vases. Later, at the end of the 6th century BC, the background of the drawing began to be painted over with black varnish, and the color of clay was left for the figures. These wali are called red-figure wali.