Scientists in the United States have developed a special coating which self-heals scratches in paintwork when exposed to sunlight.
The new compound could eventually make scratch-free cars a reality, as it can be incorporated with the conventional polymers already used to protect metallic paint.
A team at the University of Southern Mississippi in Hattiesburg developed the polyurethane coating using chitosan, a substance found in the exoskeletons of crustaceans such as crabs and shrimp.
Under ultraviolet light, the chitosan produces chemical chains which immediately begin to bond with other elements in the polymer, meaning that the damage to the chemical structure of the paint caused by scratches is gradually healed.
So far the team has only tested the coating with razor blade-sized scratches, but it has reported that it repaired any damage within an hour under appropriate conditions.
Unfortunately, the compound only works once. If a scratch occurs again in the same place then the polymer is unable to re-heal.