A security device is disclosed, comprising forming an array of focussing elements on first region of first surface of focussing element support layer, applying a pedestal layer comprising one transparent material onto first region of first surface of focussing element support layer applying transparent curable material to the pedestal layer or a casting tool carrying surface relief corresponding to focussing elements, over first region forming transparent curable material(s) with the casting tool bringing first surface of focussing element support layer against the casting tool that transparent curable material between the surface relief and the pedestal layer, across first region; and curing transparent curable material(s) on the pedestal layer to retain surface relief in first region; wherein focal length of focussing elements focal plane lies on first surface of focussing element support layer, or beyond first surface of focussing element support layer relative to the location of array of focussing elements.

A security device is disclosed, comprising forming an array of focussing elements on first region of first surface of focussing element support layer, applying a pedestal layer comprising one transparent material onto first region of first surface of focussing element support layer applying transparent curable material to the pedestal layer or a casting tool carrying surface relief corresponding to focussing elements, over first region forming transparent curable material(s) with the casting tool bringing first surface of focussing element support layer against the casting tool that transparent curable material between the surface relief and the pedestal layer, across first region; and curing transparent curable material(s) on the pedestal layer to retain surface relief in first region; wherein focal length of focussing elements focal plane lies on first surface of focussing element support layer, or beyond first surface of focussing element support layer relative to the location of array of focussing elements.

A method of manufacturing a security document, including: providing a polymer substrate having first and second surfaces; and: applying an array of focussing elements to the first surface of the polymer substrate across a first region; forming an image array by: providing a die form having a surface including an arrangement of raised areas and recessed areas defining the pattern; applying a first curable material to the surface of the die form so it substantially fills the recessed areas; bringing a pattern support layer in contact with the surface of the die form so it covers the recessed areas; separating the pattern support layer from the surface of the die form so the first curable material in the recessed areas is removed from the recessed areas and retained on the pattern support layer; and at least partly curing the first curable material in one or more curing steps.

A method of making a security device, comprising: forming an array of primary focusing elements on a first region of a focusing element support layer, by applying at least one transparent curable material either to the focusing element support layer or to a casting tool carrying a surface relief over an area which includes at least the first region, the surface relief comprising portions corresponding to the primary focusing elements; forming the transparent curable material(s) with the casting tool; and curing the transparent curable material(s) so as to retain the surface relief in the first region; wherein the surface relief further includes a plurality of structures of greater depth than the height of the primary focusing elements such that the cured transparent material(s) include a plurality of features protruding above the height of the primary focusing elements between primary focusing elements of the array.

A sheet material having a security device applied over a paper machine made or soft-edged through-hole and a method for preparing such a sheet material is provided. By way of the inventive method, the through-hole(s) is formed in a forming fibrous web before it becomes sufficiently consolidated and then the security device is applied onto the fibrous web and preferably over the through-hole(s) at or near a couch roll or similar tool of a paper machine when the fibrous web constitutes a sufficiently consolidated, fully formed wet web. Applying the security device and then further consolidating the region underlying the device at this stage of paper manufacture when the fibers would not be displaced, greatly reduces (if not eliminates) the possibility of the through-hole(s) becoming occluded or blocked. Moreover, papers made in accordance with the inventive method, when subjected to the Circulation Simulation Test, showed minimal damage at the paper/security device interface. Further, the surface-applied security devices showed acceptable levels of intaglio ink adhesion, and the papers had higher cross-direction (CD) tensile strength and much less show-through on opposing sides thereof.

A sheet material having a security device applied over a paper machine made or soft-edged through-hole and a method for preparing such a sheet material is provided. By way of the inventive method, the through-hole(s) is formed in a forming fibrous web before it becomes sufficiently consolidated and then the security device is applied onto the fibrous web and preferably over the through-hole(s) at or near a couch roll or similar tool of a paper machine when the fibrous web constitutes a sufficiently consolidated, fully formed wet web. Applying the security device and then further consolidating the region underlying the device at this stage of paper manufacture when the fibers would not be displaced, greatly reduces (if not eliminates) the possibility of the through-hole(s) becoming occluded or blocked. Moreover, papers made in accordance with the inventive method, when subjected to the Circulation Simulation Test, showed minimal damage at the paper/security device interface. Further, the surface-applied security devices showed acceptable levels of intaglio ink adhesion, and the papers had higher cross-direction (CD) tensile strength and much less show-through on opposing sides thereof.

A visual security feature is provided that is disposed on a target. The visual security feature includes two substantially transparent layers. At least one of the two substantially transparent layers is present in an image-wise pattern.

The invention provides a free flowing copolymer between disparate plastic layers to thermally balance between the two differently expanding/contracting materials. The primer layer or thermal balance layer fully encapsulates the PET layer and can absorb the difference between the internal PET layer with any layer bonded to the encapsulated PET without cracking, bending or pitting and can reset into position when the heating/cooling has ended to make planar plastic core sheets for products such as credit cards, gift cards and the like.

A method of printing a digital image includes printing authentication marks by applying an amplitude modulated raster print in a detection zone to an object, the printed area of the detection zone consisting of asymmetric raster dots, wherein at least two mutually non-parallel finder edges are printed from at least one finder zone to determine the position, boundary and orientation of the detection zone. A method of authenticating such a print includes capturing an image of the printed article; detecting the at least two finder edges to determine the detection zone from the image with halftone dot accuracy, comparing the captured print image of the detection zone with the resulting print images, and deciding on the basis of the comparison whether there is an original print on the article.

A method of printing a digital image includes printing authentication marks by applying an amplitude modulated raster print in a detection zone to an object, the printed area of the detection zone consisting of asymmetric raster dots, wherein at least two mutually non-parallel finder edges are printed from at least one finder zone to determine the position, boundary and orientation of the detection zone. A method of authenticating such a print includes capturing an image of the printed article; detecting the at least two finder edges to determine the detection zone from the image with halftone dot accuracy, comparing the captured print image of the detection zone with the resulting print images, and deciding on the basis of the comparison whether there is an original print on the article.