Minoan wall-paintings. From earliest time the Minoans used painted plaster, often in plain red, to decorate their room. By the late Minoan period, wall painting had become very elaborate. Colours, usually of mineral origin were applied to a plaster surface, often while it was still damp (true fresco technique) By far the greatest number of wall paintings in Crete come from Knossos, where walls bore figured scenes. (Photo by: Universal History Archive/UIG via Getty Images)