A substrate is printed with front side and back side markings. The front side when viewed with reflected light includes: a first marking printed with a first gradient of two colors; a second marking printed with a second gradient of two colors; a first symbol printed with a third gradient of two colors; a second symbol printed with a fourth gradient of two colors; a third symbol printed with a fifth gradient of two colors; and a fourth symbol printed with a sixth gradient of two colors. The back side when viewed with reflected light includes: a third marking printed with the fourth gradient; a fourth marking printed with the third gradient; a fifth symbol printed with the second gradient; a sixth symbol printed with the first gradient; a seventh symbol printed with the sixth gradient; and an eighth symbol printed with the fifth gradient.

An optically variable security element wherein the areal expansion whereof defines a z direction standing perpendicularly thereon, and has a multicolored, reflective areal region. The areal region includes two relief structures arranged at different height levels in the z direction. The relief structures are each supplied with an ink coating which produce a different color impression. The ink coating of the relief structure disposed at a higher level is configured in the feature region as a regular or irregular grid with grid elements and grid spaces. The dimensions of the grid elements and/or grid spaces are below 140 μm at least in one direction, so that, in the feature region, for a viewer from at least one viewing angle, the ink coating of the relief structure disposed at a lower level is visible through the grid spaces of the ink coating of the relief structure disposed at a higher level.

A display element includes a plurality of display areas, each display area including a plurality of sub display areas, each sub display area including a plurality of cells. A boundary portion formed into a groove structure so as to surround the cells. A plurality of prism structures each having a triangular cross section are arranged in parallel to each other in the cells so as to extend linearly or in an arc, and the boundary portion includes a rib structure connected to both ends of one or more of the prism structures. A display area is to display different motifs, in response to one or more of the sub display areas changing an optical property to become reflective or transmissive in accordance with one or both of an orientation angle and an elevation angle of observation.

A magnetic pigment flake includes a filtering film layer, with magnetic or magnetizable material, and a metal nanoparticles layer, formed on a surface of the filtering film layer. The metal nanoparticles layer is configured to generate scattered light enhanced by a local surface plasmon resonance under an irradiation of visible light exceeding a predetermined intensity. An optically variable ink includes an ink body and the above-mentioned magnetic pigment flakes. An anti-falsification article includes an article body and the above-mentioned optically variable ink. The magnetic pigment flake of the optically variable ink is magnetically oriented, such that a bright and dark areas are generated with a viewing angel changing under an irradiation of visible light below the predetermined intensity. Under an irradiation of visible light exceeding the predetermined intensity, light with a color different from that of the bright area is generated on a corresponding position of the dark area.

A magnetic pigment flake includes a filtering film layer, with magnetic or magnetizable material, and a metal nanoparticles layer, formed on a surface of the filtering film layer. The metal nanoparticles layer is configured to generate scattered light enhanced by a local surface plasmon resonance under an irradiation of visible light exceeding a predetermined intensity. An optically variable ink includes an ink body and the above-mentioned magnetic pigment flakes. An anti-falsification article includes an article body and the above-mentioned optically variable ink. The magnetic pigment flake of the optically variable ink is magnetically oriented, such that a bright and dark areas are generated with a viewing angel changing under an irradiation of visible light below the predetermined intensity. Under an irradiation of visible light exceeding the predetermined intensity, light with a color different from that of the bright area is generated on a corresponding position of the dark area.

The present disclosure is directed towards a security sheet (10) for displaying personal data (11) comprising a plastic substrate (12) comprising first and second outer surfaces (13, 14). A first opaque region (21) extends partially across the plastic substrate (12) between the first and second outer surfaces (13, 14). A first window (50) is at least partially surrounded by the first opaque region (21). A security device (51) comprises a transparent first device region (52) and a second device region (53) formed from a second device insert (55). The first and second device regions (52, 53) have different optical detection characteristics. The security device (51) is arranged in the plastic substrate (12) such that, when viewed in reflected light incident upon the first outer surface (13), at least part of the first device region (52) is visible at least partially around the second device region (53) in the first window (50).

A security device includes an array of lenses and a plurality of first and second segments disposed under the array of lenses. At a first viewing angle, the array of lenses presents a first image for viewing without presenting the second image for viewing, and at a second viewing angle different from the first viewing angle, the array of lenses presents for viewing the second image without presenting the first image for viewing. At least one first or second segment can include one or more microstructures or one or more nanostructures configured to produce one or more colors for the first or second image.

A security device includes an array of lenses and a plurality of first and second segments disposed under the array of lenses. At a first viewing angle, the array of lenses presents a first image for viewing without presenting the second image for viewing, and at a second viewing angle different from the first viewing angle, the array of lenses presents for viewing the second image without presenting the first image for viewing. At least one first or second segment can include one or more microstructures or one or more nanostructures configured to produce one or more colors for the first or second image.

A lens pigment suitable for manufacturing value documents by printing technology, includes a carrier substrate which forms a lens base and which is supplied on its front side with a first plastic having at least one elevation that produces a microlens and with a second plastic leveling the first plastic.

A lens pigment suitable for manufacturing value documents by printing technology, includes a carrier substrate which forms a lens base and which is supplied on its front side with a first plastic having at least one elevation that produces a microlens and with a second plastic leveling the first plastic.