A security device is disclosed, comprising: a first ink (21) and a second ink (22) each arranged in respective laterally offset first and second regions of the security device, the first and second inks each comprising a respective luminescent material which both luminesce in response to irradiation at at least one excitation wavelength in the ultra-violet spectrum, the first and second inks each exhibiting substantially the same non-luminescent visible colour as one another when illuminated with visible light in the absence of the at least one excitation wavelength, and the first and second inks each exhibiting visible colours which are different from the non-luminescent visible colour and from one another when illuminated with a combination of visible light and the at least one excitation wavelength; a third ink (23) arranged in a third region of the device laterally offset from the first and second regions of the device, the third ink not luminescing in response to the at least one excitation wavelength, and the third ink exhibiting substantially the same non-luminescent visible colour as the first and second inks when illuminated with visible light in the absence of the at least one excitation wavelength; and a fourth ink (24) arranged in a masking pattern which partially overlaps one or more portions of the first ink in the first region and/or of the second ink in the second region, the fourth ink not luminescing in response to the at least one excitation wavelength, and the fourth ink exhibiting a different visible colour from the non-luminescent visible colour of the first, second and third inks when illuminated with visible light in the absence of the at least one excitation wavelength. When the security device is illuminated with visible light in the absence of the at least one excitation wavelength, the first, second and third regions together appear as one continuous pattern in the non-luminescent visible colour, the fourth ink obscuring the presence of more than one ink forming the continuous pattern, and when the security device is illuminated with a combination of visible light and the at least one excitation wavelength, the first and second regions become visibly distinct from each other and from the remainder of the continuous pattern.

The present invention relates to the field of the intaglio printing process. In particular, the present invention relates to a method that combines intaglio inks curable by oxidation with UV-VIS-curable intaglio inks on one intaglio plate or cylinder. The disclosed method results in an intaglio printed security element using advantageously the unalike properties of the different inks while enabling the printing on a standard printing press in one printing step.

The present invention relates to the field of the intaglio printing process. In particular, the present invention relates to a method that combines intaglio inks curable by oxidation with UV-VIS-curable intaglio inks on one intaglio plate or cylinder. The disclosed method results in an intaglio printed security element using advantageously the unalike properties of the different inks while enabling the printing on a standard printing press in one printing step.

The present invention provides photoluminescent iron-doped barium stannate materials absorbing ultraviolet (UV) light and exhibiting strong near-infrared (NIR) luminescence. Such materials exhibit increased integrated photoluminescence intensity in comparison to known BaSnO.sub.3 and iron-doped barium stannate materials, and therefore they are particularly useful for the production of photoluminescent security ink compositions and transparent covert security features with improved anti-counterfeiting resistance that can be used for protection of documents and articles against counterfeit and illegal reproduction.

The present invention provides photoluminescent iron-doped barium stannate materials absorbing ultraviolet (UV) light and exhibiting strong near-infrared (NIR) luminescence. Such materials exhibit increased integrated photoluminescence intensity in comparison to known BaSnO.sub.3 and iron-doped barium stannate materials, and therefore they are particularly useful for the production of photoluminescent security ink compositions and transparent covert security features with improved anti-counterfeiting resistance that can be used for protection of documents and articles against counterfeit and illegal reproduction.

The present invention relates to the field of the intaglio printing process. In particular, the present invention relates to a method that combines intaglio inks curable by oxidation with UV-VIS-curable intaglio inks on one intaglio plate or cylinder. The disclosed method results in an intaglio printed security element using advantageously the unalike properties of the different inks while enabling the printing on a standard printing press in one printing step.

The present invention relates to the field of the intaglio printing process. In particular, the present invention relates to a method that combines intaglio inks curable by oxidation with UV-VIS-curable intaglio inks on one intaglio plate or cylinder. The disclosed method results in an intaglio printed security element using advantageously the unalike properties of the different inks while enabling the printing on a standard printing press in one printing step.

An information recording medium is formed by laminating a transparent protective layer and a base material having laser color-developing properties. The information recording medium includes an intermediate layer that is disposed between the transparent protective layer and the base material. In the information recording medium, the intermediate layer includes a diffraction structure layer that has a diffraction structure, and a first reflective layer that reflects visible light and is destroyed when irradiated with a laser beam. Light, when incident from a transparent protective layer side, causes a diffracted light pattern to appear in the diffraction structure layer so as to be observable from the transparent protective layer side. A laser beam, when applied from the transparent protective layer side, passes through the diffraction structure layer, destroys the first reflective layer, and develops color in the base material.

An information recording medium is formed by laminating a transparent protective layer and a base material having laser color-developing properties. The information recording medium includes an intermediate layer that is disposed between the transparent protective layer and the base material. In the information recording medium, the intermediate layer includes a diffraction structure layer that has a diffraction structure, and a first reflective layer that reflects visible light and is destroyed when irradiated with a laser beam. Light, when incident from a transparent protective layer side, causes a diffracted light pattern to appear in the diffraction structure layer so as to be observable from the transparent protective layer side. A laser beam, when applied from the transparent protective layer side, passes through the diffraction structure layer, destroys the first reflective layer, and develops color in the base material.

The present invention relates to a method of manufacturing a substrate with an embedded, UV-visible pattern, wherein a liquid treatment composition comprising at least one acid is deposited onto a substrate, which comprises at least one optical brightener and optionally a filler, wherein the filler comprises 0 to 60 wt.-% of a salifiable alkaline or alkaline earth compound, based on the total weight of the substrate.