FIELD: physics.
SUBSTANCE: method of producing a layer with an optical effect (LOE) on a substrate containing a photomask, where said LOE contains a motif made of at least two regions, preferably, at least two adjacent areas made from a single hardened layer, the method comprising steps of: depositing on a substrate containing a photomask a radiation curable coating composition containing one or more photo initiators and a plurality of magnetic or magnetisable pigment particles, to form a coating layer, wherein said coating layer is in a first state and said coating layer at least partially faces the photomask; one or more first substrate regions carrying a coating layer are cured through a substrate, wherein said hardening is carried out by irradiating with the help of UV and visible radiation source, to second state for fixation or retention of magnetic or magnetisable particles in their positions and with their orientations; and subjecting at least one or more second areas of the substrate carrying the coating layer, which are in the first state due to the presence of the substrate photomask, the magnetic field of the device generating the magnetic field, thereby orienting a plurality of magnetic or magnetisable pigment particles such that they follow any orientation pattern of magnetic or magnetisable pigment particles, except for random orientation; and simultaneously, partially simultaneously or subsequently cured by irradiation with the help of UV and visible radiation source of at least one or more second areas of substrate, carrying coating layer, to second state for fixation or retention of magnetic or magnetisable particles in their received positions and with their received orientations, where the photomask has an optical density DM equal to or higher than 1.0, preferably equal to or higher than 1.1 and more preferably equal to or greater than 1.2.
EFFECT: invention relates to protection of security documents, such as, for example, banknotes and identity documents, against counterfeiting and illegal reproduction.
15 cl, 39 dwg
