Russian physicists have proposed a method to develop nanoimage providing maximum protection of money, bank cards and documents from counterfeiting. The new technology is based on an instant cultivation of metal nanocrystals in paper or plastic, reported ИТАР-ТАСС project leader prof. Sergei Maksimovskiy.
Heavy-duty laser bores tiny pores or micro-mine in the paper, with the approximate depth of half the thickness of the sheet and a diameter of 10 microns. The temperature of the laser flash reaches 3.5 thousand degrees, but its duration is insignificant less than 0.01 seconds. Paper does not flame, but the metals melt from solution and the crystals grow on the walls of the pores.