“In south-western France before about 25,000 to 20,000 BC animals were incised in bold outline on the walls of caves. From about 18,000 BC red, black and yellow pigments were also being used, especially for stencil impressions of hands, many of them with disturbingly mutilated fingers. Such “drawings” hardly prepare us, however, for the cave paintings. . . .
The earliest paintings in the most famous of the caves, Lascaux, seem to date from about 15,000 BC. During the following 5,000 years or so, cave painting continues with unchanging consistency, apart from slight local variations. . . . When the first examples were found at Altamira in northern Spain in 1879 most archeologists dismissed them as a hoax perpetrated by an artist friend of the caves’ owner: few were able to believe that they could be prehistoric. Subsequent discoveries, especially those at Lascaux made by accident in 1940, left no doubt that they are Paleolithic, and scientific methods of dating have now established their approximate age. Their technique has also been analyzed. The pigments were derived from natural minerals—reds, yellows and browns from ochre and hematite; black, dark brown and violet from various types of manganese. These substances were ground to powder and applied directly on to the damp limestone walls and ceilings of the caves. First the outlines were painted with pads of fur or mosss, with primitive brushes of fur, feather or chewed stick, or simply with a finger, and then the outlines were filled in by spraying powders thorugh bone tubes. (Such tubes with traces of colour have been found in the caves.)”

—Hugh Honour & John Fleming, from The Visual Arts: A History, 1982.