A security device (100, 900) includes an arrangement of image icon focusing elements (120, 605, 705), wherein each image icon focusing element of the arrangement of image icon focusing elements is associated with a focal path. The device further includes an image icon layer with one or more image icons (110a, 909) associated with a first characteristic color and one or more image icons (110b, 911) associated with a second characteristic color, and one or more regions between image icons comprising a volume of substantially colorless material. At a first viewing angle, a color is visible through each image icon focusing element, and the color visible through each image icon focusing element at the first viewing angle is based on one or more of the first characteristic color, the second characteristic color, or the substantially colorless material.

A security device (100, 900) includes an arrangement of image icon focusing elements (120, 605, 705), wherein each image icon focusing element of the arrangement of image icon focusing elements is associated with a focal path. The device further includes an image icon layer with one or more image icons (110a, 909) associated with a first characteristic color and one or more image icons (110b, 911) associated with a second characteristic color, and one or more regions between image icons comprising a volume of substantially colorless material. At a first viewing angle, a color is visible through each image icon focusing element, and the color visible through each image icon focusing element at the first viewing angle is based on one or more of the first characteristic color, the second characteristic color, or the substantially colorless material.

The present invention relates to a method of tagging a substrate with a covert, spectroscopically detectable security feature, wherein a liquid treatment composition comprising at least one acid is deposited onto a substrate, which comprises at least one external surface comprising a salifiable alkaline or alkaline earth compound.

The present invention relates to a method of tagging a substrate with a covert, spectroscopically detectable security feature, wherein a liquid treatment composition comprising at least one acid is deposited onto a substrate, which comprises at least one external surface comprising a salifiable alkaline or alkaline earth compound.

A chelate and associated security feature including a lanthanide metal and a ligand of formula (1), formula (2), or formula (3),

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where each of R.sub.1-R.sub.7 in formula (1) is independently selected from the group consisting of H, OH, NH.sub.2, Cl, F, OMe, OAr, OCF.sub.3, CF.sub.3, alkyl, aryl, phenyl, OPh, and heteroaromatic, where each of R.sub.1-R.sub.5 in formula (2) is independently selected from the group consisting of H, OH, NH.sub.2, Cl, F, OMe, OAr, OCF.sub.3, CF.sub.3, NMe.sub.2, CN, alkyl, aryl, phenyl, OPh, and heteroaromatic, and where R.sub.6 in formula (2) is selected from the group consisting of H, NH.sub.2, Cl, F, OMe, OAr, OCF.sub.3, CF.sub.3, NMe.sub.2, CN, alkyl, aryl, phenyl, OPh, and heteroaromatic, and where each of R.sub.1-R.sub.5 in formula (3) is independently selected from the group consisting of H, OH, NH.sub.2, Cl, F, OMe, OAr, OCF.sub.3, CF.sub.3, alkyl, aryl, phenyl, OPh, and heteroaromatic.

An object of the present invention is to provide a thin volume hologram sheet to be embedded sufficiently resistant to a mechanical stress such as a stress including a tensile stress, a shear stress and a compression stress at the time of processing even under a heating condition, a forgery prevention paper and a card using the same. The object is achieved by providing a volume hologram sheet to be embedded comprising a volume hologram layer, and a substrate disposed only on one side surface of the volume hologram layer using an adhesion means, wherein a peeling strength of the volume hologram layer and the substrate is 25 gf/25 mm or more.

An object of the present invention is to provide a thin volume hologram sheet to be embedded sufficiently resistant to a mechanical stress such as a stress including a tensile stress, a shear stress and a compression stress at the time of processing even under a heating condition, a forgery prevention paper and a card using the same. The object is achieved by providing a volume hologram sheet to be embedded comprising a volume hologram layer, and a substrate disposed only on one side surface of the volume hologram layer using an adhesion means, wherein a peeling strength of the volume hologram layer and the substrate is 25 gf/25 mm or more.

A security document (e.g. passport) comprising a protective feature for authenticating a laminate data sheet thereof and method for making the same. A metalized flexible hinge attached to the laminate data sheet is used to bind the laminate data sheet into the passport with one or more other sheets at a binding of the passport such that at least a portion of the metalized surface of the flexible hinge is visible proximate to the laminate data sheet. Personalization data is etched on the visible portion of the metalized surface of the flexible hinge and matches personalization data of the laminate data sheet.

A security document (e.g. passport) comprising a protective feature for authenticating a laminate data sheet thereof and method for making the same. A metalized flexible hinge attached to the laminate data sheet is used to bind the laminate data sheet into the passport with one or more other sheets at a binding of the passport such that at least a portion of the metalized surface of the flexible hinge is visible proximate to the laminate data sheet. Personalization data is etched on the visible portion of the metalized surface of the flexible hinge and matches personalization data of the laminate data sheet.

A method for preparing a large-area structural chromogenic pattern by ink-jet printing, a structural chromogenic pattern obtained by the method, and an anti-counterfeiting method based on a structural color change. A dispersion liquid containing mono-disperse colloidal microspheres with high index of refraction is printed onto a piece of paper by using an ink-jet printer, and nano-microspheres are arranged and assembled on the paper to obtain a micro-structure having the features of being ordered from a short distance and disordered from a long distance. A pretty structural color can be observed by means of the interaction of the structure with light, thus displaying a pattern, changing the angle of observation, changing the brightness of the structural color, and hiding and displaying the pattern. The method is simple and convenient, is widely applicable, and can achieve the preparation and anti-counterfeiting of a large-area structural color without external stimulation.