FIELD: printing equipment.
SUBSTANCE: invention relates to special types of printing and enables to obtain an original image inside sheet paper for counterfeit protection of security papers. In compliance with this invention, green paper is used to insert sheet paper into said sheet from laser-transparent plastic, on opposite surfaces of which there are continuous diffusion gratings deepened in its surface. Metal-coated diffraction grating is successively coated on one side of the filament with a layer of plastic which is transparent to laser radiation and a metal layer. Then, the specified points of the surface of the sheet paper are exposed to laser radiation pulses to create an image in the filament from points poured by rainbow colours and visible through channels created in sheet paper by laser radiation pulses.
EFFECT: higher reliability of protection of securities from counterfeiting.
1 cl, 2 dwg
