The patina is darker on the older images and the newer images are brighter.
To progress, it is essential to apply the second type, or relative, dating.
The term refers to the fact that an approximate date can be inferred by comparison with something else of known age.
Compared to subsequent periods, the older Holocene Wet Phase Neolithic images usually have a patina that formed after the art and is evenly dispersed over both the images and the background.
Later petroglyph artists took advantage of desert varnish, a dark, often shiny glaze that forms on rock surfaces in very arid environments.
Clues to relative dating include: the manufacturing technique used; the patina covering the art; the layering of figures on top of each other; the style of human forms; and the particular animal species, types of artifacts and subject matter shown.
For some 20,000 years, during the Late Pleistocene epoch (Ice Age), the Arabian Peninsula was overall very arid, as it is today.
This is not typical of the rock art in Saudi Arabia, however, which tends to be exposed and lacking any settlement or camp next to the cliff face.
A palimpsest of animals from different ages at Shuwaymis: Faint images of Neolithic aurochsen (wild cattle), more recent camels and cavalryman, still younger men with exaggerated hands.
Given the current status of direct chronometric dating methods for Arabian petroglyphs, it is rare that the precise age of a rock art panel can be determined.