Respuesta :
The artist filled in the lines with black or dark brown to give it a firm edge. And the Animal was filled in with different shades of reddish brown hue. That shading technique helped create the impression of a three-dimensional form.
They used primitive shading techniques. This would give the appearance of depth to the pictures, as well as showing movement. In addition, this would firm up the edges and make the images more life-like. In addition, using different colors on the drawings helped to give a three-dimensional appearance.