The invention relates to a method for producing a security feature (1) in the form of a colored image (2), a colorant being applied to a substrate (3) to produce the image, the image (2) being subdivided into grid areas, immediately adjacent grid areas (4, 5, 6, 9, 10, 11) of the image (2) partially overlapping, an overlapping area (7, 8) of immediately adjacent grid areas (4, 5, 6, 9, 10, 11) being smaller than one of the grid areas (4, 5, 6, 9, 10, 11), grid areas (4, 5, 6, 9, 10, 11) of the image (2) being each assigned at least one color, and at least the areas of the substrate (3) corresponding to the respective grid areas (4, 5, 6, 9, 10, 11) minus the corresponding overlapping areas (7, 8) being covered with at least one colorant of the respectively assigned color, the overlapping areas (7, 8) between adjacent grid areas (4, 5, 6, 9, 10, 11) being covered at least with the colorant having the color assigned to one of the grid areas (4, 5, 6, 9, 10, 11) overlapping in the respective overlapping areas (7, 8).

Techniques for manufacturing a light field print using a printing press. The techniques include: identifying at least one characteristic of the printing press at least in part by printing at least one calibration pattern; obtaining content to be rendered using the light field print, the content comprising multiple scene views; generating, based at least in part on the content and the at least one characteristic of the printing press, a front target pattern and a back target pattern; and using the printing press to: print the front target pattern on a first side of a substrate; and print the back target pattern on a second side of the substrate.

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 absorbance or emission wavelength of composite materials comprising a transition metal doped shell disposed over a rare earth doped core and a functionalizable group on the surface of the transition metal doped shell can change upon subjection to a carboxylic acid. This method of changing the absorbance or emission wavelength of a composite material can be used to identify counterfeit currency using an ink comprising a composite material.

An example container includes: structure having an interior and an exterior. The interior is to contain an electronic product. The exterior comprises: a first label of a first type of polychromatic ink to be activated at a first wavelength; and a second label of a second type of polychromatic ink to be activated at a second wavelength different from the first wavelength; the first label to indicate a first set of features to be configured at the electronic product using a first wireless signal; and the second label to indicate a second set of features to be configured at the electronic product using a second wireless signal. The structure is transparent to the first wireless signal and the second wireless signal.

A solid fluorescence standard that can be used to calibrate and/or normalize a device (e.g., a scientific instrument) that is configured for generating and collecting fluorescence data. A fluorescence standard disclosed herein includes an adhesive (e.g., a low viscosity, substantially optically transparent, solvent-free, radiation curable adhesive, such as, but not limited to, a UV curable adhesive), and a selected quantity of fluorescent particles (e.g., quantum dots) dispersed in the adhesive. The adhesive and the fluorescent particles are mixed together and disposed in a sample well. The adhesive is then cured and solidified, which yields a solid fluorescence standard in the well.

A security device includes a luminescent material arranged in a first region, wherein the material luminesces in response to irradiation one excitation wavelength wherein the first region exhibits a luminescent visible colour; an array of viewing elements; and a masking layer positioned between the decorative layer and the array of viewing elements, the masking layer partially overlaps with first region, including first pattern elements defined by the masking material, and second pattern elements defined by the absence of the masking material wherein the decorative layer is visible through the second pattern elements; the masking material is non-luminescing in response to one excitation wavelength, and when the security device illuminates by at least one wavelength, where the array of pattern elements overlaps with the first region, the second pattern elements exhibit the luminescent visible colour, and the first pattern elements exhibit a visual appearance that's different to the luminescent visible colour.

A forgery prevention medium includes a substrate and a specific invisible material layer directly or indirectly laminated on the substrate, having a specific invisible material reversibly and visually recognized through a predetermined process disposed thereon in a plane shape, and having a part of the specific invisible material inactivated in accordance with a visualized image pattern.

A digitally printed security document includes: a security document substrate; a first digitally printed print working on a first surface of the substrate in a first region, the first print working including a first array of printed elements arranged according to a first grid of lattice points having a first pitch; and a second digitally printed print working on the first surface of the substrate in a second region, the second print working including a second array of printed elements arranged across a second grid of lattice points having a second pitch different from the first pitch.

The absorbance or emission wavelength of composite materials comprising a transition metal doped shell disposed over a rare earth doped core and a functionalizable group on the surface of the transition metal doped shell can change upon subjection to a carboxylic acid. This method of changing the absorbance or emission wavelength of a composite material can be used to identify counterfeit currency using an ink comprising a composite material.