A deposition device may deposit, on a substrate, a binder layer that includes a first set of magnetic flakes and a second set of magnetic flakes and may cause, when a temperature of the binder layer satisfies a temperature threshold (e.g., a Curie temperature of the first set of magnetic flakes), a magnetic field to be applied to the binder layer to cause the first set of magnetic flakes and the second set of magnetic flakes to be oriented according to the magnetic field. The deposition device may cause, when the temperature of the binder layer ceases to satisfy the temperature threshold, another magnetic field to be applied to the binder layer to cause only the second set of magnetic flakes to be oriented according to the other magnetic field.

The invention relates to the field of the protection of security documents such as for example banknotes and identity documents against counterfeit and illegal reproduction. In particular, the invention relates to optical effect layers (OEL) showing a viewing-angle dependent optical effect, devices and processes for producing said OEL and items carrying said OEL, as well as uses of said optical effect layers as an anti-counterfeit means on documents. The OEL comprises a plurality of non-spherical magnetic or magnetizable particles, which are dispersed in a coating composition comprising a binder material, wherein in at least a loop-shaped area of the OEL at least a part of the plurality of non-spherical magnetic or magnetizable particles are oriented such that their longest axis is substantially parallel to the plane of the OEL, and wherein, in a cross-section perpendicular to the OEL and extending from the center of the central area, the longest axis of the oriented particles present in the loop-shaped area forming the impression of the loop-shaped body follow a tangent of either a negatively curved or a positively curved part of a hypothetical ellipse or circle.

Systems and methods relate generally to a concealable marking. In an example, obtained is a printing device having a printhead, a plasma head, a platform, and a stencil holder. The printhead is configured to print to a surface of a medium. The plasma head is configured to provide a plasma. The platform is configured to support and transport the medium. The stencil holder is configured to hold a stencil between the surface of the medium and the plasma head. A region of the surface of the medium is covered with the stencil. The stencil defines at least one opening for exposure of a portion of the region of the surface. A plasma is generated with the plasma head. The portion of the surface of the medium is exposed to the plasma through the at least one opening to hydrophilize the portion of the surface thereof to provide the concealable marking.

A security document, including: a polymer substrate; at least one print layer disposed on one or both sides of the polymer substrate; and a security feature including an image area embodied within the polymer substrate and at least partially covered by the at least one print layer, wherein the security feature is an optical security feature formed in the image area.

The invention relates to a transfer film (1), in particular hot-stamping film, the use of a transfer film (1), a film, a security document (2), and a method for producing a transfer film (1). Here, it is provided that the transfer film (1) comprises a transfer layer (20) detachably arranged on a carrier layer (10). The transfer layer (20) further has at least one first color layer (30) and the at least one first color layer (30) comprises at least one binder and at least first pigments, the color appearance of which changes depending on the observation angle.

A method of authenticating and/or identifying a security article including a first image includes superimposing at least partially the first image of the article with a second image. The second image may be produced by an electronic imager. The method further includes performing a relative movement between the first and second images so as to make it possible to observe an item of information relating to authentication and/or identification of the security article during the relative movement between the first and second images.

The present invention relates to the use of coating compositions, comprising shaped transition metal, especially silver, particles and a binder, wherein the ratio of pigment to binder is preferably such that the resulting coating shows an angle dependent color change, for the production of security elements and holograms. When the coating compositions of the present invention are used in coating a hologram the obtained products show a an angle dependent color change (flip/flop effect), different colors in reflection and transmission, an extremely bright OVD image and extremely strong rainbow effect, high purity and contrast.

A digital printing press for printing security documents is provided. The digital printing press comprises: a first digital print head, the first digital printhead comprising a first array of print nozzles having a first nozzle diameter; a second digital print head, the second digital print head comprising a second array of print nozzles having a second nozzle diameter different from the first nozzle diameter; optionally, an offset printing unit, the offset printing unit comprising one or more offset printing surfaces, wherein the offset printing unit is adapted to transport a print area of the one or more offset printing surfaces sequentially past each of the first and second digital print heads, and subsequently to transfer print received from the first and second digital print heads to a security document substrate; a transport system adapted to transport a security document substrate along a transport path through the digital printing press, wherein either the transport path takes the security document sequentially past each of the first and second digital print heads in a feed direction, or the transport path takes the security document substrate past the offset printing unit, if provided, in a feed direction; a controller adapted to control both the first and second digital print heads to execute a set of printing instructions so as to print on a security document substrate transported past the first and second digital print heads by the transport system or to print on the print area of the one or more offset printing surfaces transported past the first and second digital print heads by the offset printing unit (and to transfer the print received on the print area of the offset printing to the security document substrate), the set of printing instructions including printing instructions at a first resolution for the first digital print head for printing a first print working and printing instructions at a second resolution different from the first resolution for the second digital print head for printing a second print working; wherein the first digital print head is configured to print at the first resolution and the second digital print head is configured to print at the second resolution, and wherein the first and second digital print heads are configured or controlled by the controller to remain static relative to the transport path or offset printing unit while the first and second digital print heads execute the respective printing instructions.

An optical device including: a colour shifting layer that exhibits different colours dependent on the angle of incidence of incident light; first and second arrays of at least partially transparent microstructures covering at least part of the layer, configured to modify angle of light to generate a first optically variable effect, wherein: the first array is arranged as a set of image elements that cooperate to exhibit a first image, and the second is arranged to exhibit a second image, wherein the elements of the first array are interlaced with those of the second, and, the microstructures have at least one face that reflects incident light, whereby the first array is configured so, when viewed along a first viewing direction the device exhibits the first image, and the second is configured so, when viewed along a second direction the device exhibits the second image. Also, methods of manufacturing the device.

A method for building a security image for a security structure of a security document from multiplexing color images, including selecting a marking method capable of producing sets of colors on the security document comprising different colors that can be displayed according to illumination/observation modes of the security structure, establishing a plurality of color sets that can be displayed by the security structure in a plurality of the different illumination/observation modes, distributing the color sets in a plurality of groups of color sets, establishing combinations of groups of color sets having at least one color set in common across the number of different illumination/observation modes, selecting a combination of a group of color sets based on the number of desired illumination/observation modes and the number of colors per color image, and determining the color images to multiplex by means of the combination of the group of color sets selected.