What did the Paleolithic people use for writing, like on walls and on rocks? If it was paint, how did they turn their resources into paint?
   Amanda, 16, Stratford, Ontario, Canada

Dr. dig responds:
The Palaeolithic (Old Stone Age) people decorated their cave walls either by carving or engraving them with sharp stones, or by painting them with pigment made from minerals. Red (rust) colors were obtained from iron oxide; black came either from charcoal or manganese dioxide; and white, which was rarely used, came from kaolin or kaolinite. These minerals were ground up on pestles and mortars, and combined to produce a variety of colors. They were then mixed with water to make paint. Archaeologists used to think that the pigments were mixed with oils or fats, but experiments have shown that this does not work. The paints were applied to the walls either with fingers, fur, or brushes made from twigs. It may be that the artists also used blues and greens obtained from plants such as woad, but these colors have faded from the walls, and so we cannot be certain of this.