The invention relates to a security feature for safeguarding value documents, comprising particles which are composed of at least two different, spatially separate solid homogeneous phases, wherein each of the phases is detectable and identifiable in a spatially resolved manner by means of a spatially resolving analytical method that is adapted for resolving down to the single-particle level.

A display includes a first optical effect layer including a first interface part, the first interface part being provided with recesses or protrusions arranged two-dimensionally at the minimum center-to-center distance in a range of 200 nm to 500 nm, each of the recesses or protrusions having a forward-tapered shape; a reflective material layer covering at least a part of the first interface part; and a second optical effect layer including, at a position of a first portion of the first interface part that is covered with the reflective material layer, a portion that faces the reflective material layer with the first optical effect layer interposed therebetween or faces the first optical effect layer with the reflective material layer interposed therebetween, the second optical effect layer containing at least one of a cholesteric liquid crystal, a pearl pigment and a multilayer interference film.

A display includes a first optical effect layer including a first interface part, the first interface part being provided with recesses or protrusions arranged two-dimensionally at the minimum center-to-center distance in a range of 200 nm to 500 nm, each of the recesses or protrusions having a forward-tapered shape; a reflective material layer covering at least a part of the first interface part; and a second optical effect layer including, at a position of a first portion of the first interface part that is covered with the reflective material layer, a portion that faces the reflective material layer with the first optical effect layer interposed therebetween or faces the first optical effect layer with the reflective material layer interposed therebetween, the second optical effect layer containing at least one of a cholesteric liquid crystal, a pearl pigment and a multilayer interference film.

A recording medium is provided, such as paper, secured by magnetic microwires. The recording medium comprises: a pulp structure formed by pulp fibers, said pulp structure carrying microwires having a metal core of a predetermined material composition, and an insulating layer coating on said metal core; and at least one coating layer on at least one side of said pulp structure. The pulp structure is a single-layer structure with the microwires fully embedded in said single layer, the microwires having cross-sectional dimensions approximately equal to cross-sectional dimensions of the pulp fibers.

A recording medium is provided, such as paper, secured by magnetic microwires. The recording medium comprises: a pulp structure formed by pulp fibers, said pulp structure carrying microwires having a metal core of a predetermined material composition, and an insulating layer coating on said metal core; and at least one coating layer on at least one side of said pulp structure. The pulp structure is a single-layer structure with the microwires fully embedded in said single layer, the microwires having cross-sectional dimensions approximately equal to cross-sectional dimensions of the pulp fibers.

A security document (1) comprises a paper document substrate (11) and a security element (2) embedded in said document substrate (11). The security element comprises an element substrate (21) and a material (22) sensitive to laser light. The method comprises the step of directing laser light (41) onto the document substrate (11) so as to alter said material (22), so as to provide said security element (2) with a detectable marking (3).

A security document (1) comprises a paper document substrate (11) and a security element (2) embedded in said document substrate (11). The security element comprises an element substrate (21) and a material (22) sensitive to laser light. The method comprises the step of directing laser light (41) onto the document substrate (11) so as to alter said material (22), so as to provide said security element (2) with a detectable marking (3).

A fluorescence and phosphorescence detection device includes a fluorescence and phosphorescence sensor, a data acquiring unit, and an emission detection unit. The fluorescence and phosphorescence sensor includes a light source that emits an excitation light of a predetermined wavelength, and a photodetection unit that detects fluorescence emission and phosphorescence emission excited from the paper sheet by the excitation light. The data acquiring unit acquires a time-series waveform of a signal outputted from the fluorescence and phosphorescence sensor in response to the detection of the emission in the photodetection unit. The emission detection unit detects the fluorescence emission from the time-series waveform of a period in which the excitation light is emitted from the light source and detects the phosphorescence emission from an attenuation curve appearing on the time-series waveform of a period in which emission of the excitation light from the light source is stopped.

A thermochromic ink and, particularly, to a thermochromic ink produced by combining an anthocyanidin extract with alginate. The thermochromic ink can be used for authentication purposes produced by combining an anthocyanidin (ACYD)-based Brassica oleracea L. var. capitata extract with an alginate (ALG). To increase the anthocyanidin/alginate ink stability, a mordant (ferrous sulfate) can be used to link the anthocyanidin biomolecules with the alginate.

A thermochromic ink and, particularly, to a thermochromic ink produced by combining an anthocyanidin extract with alginate. The thermochromic ink can be used for authentication purposes produced by combining an anthocyanidin (ACYD)-based Brassica oleracea L. var. capitata extract with an alginate (ALG). To increase the anthocyanidin/alginate ink stability, a mordant (ferrous sulfate) can be used to link the anthocyanidin biomolecules with the alginate.