Can you guess when the first interior walls were being painted? Cave Paintings! The paints used would have been made with different combinations of animal fat, clay, earth, soot, and groundwater. And for a change of colour, they would have used Bison blood! In the 1600s, paint was made by grinding pigment and oil with a common mortar and pestle. This would make a thick paste - something that is still used today, but at a higher price then those that are mass-produced. It wasn