The present invention relates to a method for producing water-insoluble quantum dot patterns on and/or within a substrate. The method comprises a step of depositing a deliquescent salt, quantum dots and an acid or salt thereof onto at least one surface region of a substrate such that the deliquescent salt, the quantum dots and the acid or salt thereof are at least partially contacted to form said at least one water-insoluble pattern.

The present invention relates to method of manufacturing a tamper-proof medium for thermal printing, wherein a liquid treatment composition comprising at least one acid is deposited on a substrate which comprises a thermochromic coating layer comprising at least one halochromic leuco dye.

Developing agent precursors and laser markable compositions including such developing agent precursors.

A laser markable composition has an improved stability towards the environment by using specific Near Infrared absorbing compounds.

Embodiments relate to producing micro-image elements on a substrate for a security document, the method comprising: producing a plurality of microstructure units comprising three-dimensionally structured formations in a clear or pale relief layer on the substrate; and applying a coloured ink fluid to the relief layer, wherein the coloured ink fluid accumulates preferentially in regions of high surface curvature on each microstructure unit to provide contrasting areas of different ink density.

The present invention relates to a method for creating a hidden pattern on a substrate, wherein a liquid treatment composition comprising at least one acid is deposited by inkjet printing onto a substrate, which comprises at least one external surface comprising a salifiable alkaline or alkaline earth compound.

According to one embodiment, a recording medium is a recording medium in a card form. The recording medium includes a substrate, and a color development layer laminated on the substrate, and provided with a line for security that extends along a lamination surface of the substrate from an end face of the recording medium, such that presence or absence of the line for security is optically identifiable at the end face. It is thus provided a recording medium that can easily prevent falsification with a simple structure, and allows authenticity determination to be performed relatively easily.

As a thermosensitive recording medium utilizes a coloring reaction between a colorless or pale colored electron donating leuco dye and an electron accepting color developing agent, a thermosensitive recording medium using an environment-friendly color developing agent is provided. Provided is a thermosensitive recording medium having a thermosensitive recording layer comprising a colorless or pale colored electron donating leuco dye and an electron accepting color developing agent on a substrate, wherein the thermosensitive recording layer comprises a gluconolactone as the electron accepting color developing agent.

A method for producing a security document, with a thermographic substrate wherein the thermographic substrate is caused to undergo a color change depending on temperature effect in at least one first region A film element is arranged in such a way that the film element is arranged between the at least one first region of the thermographic substrate and a thermal print head. At least one first item of information is introduced by means of the thermal print head by activation of the color change in the at least one first region of the thermographic substrate, wherein the thermal print head, during the introduction of the at least one first item of information is in contact with the film element in such a way that the temperature effect causing the activation of the color change is transferred from the thermal print head through the film element to the at least one first region of the thermographic substrate.

A method for continuously or semi-continuously numbering, QR coding and/or barcoding of banknotes comprises the following steps: i) providing a substrate in form of a sheet of (security) paper or of a sheet of (security) polymer foil or a (security) composite comprising at least one security paper layer and at least one security polymer foil, ii) printing onto each of the two surfaces of the substrate sheet each one or more printing ink layers so as to generate a plurality of banknotes on the substrate sheet, wherein each printing ink layer extends over a part or the whole of the surface area of the substrate sheet, and wherein the printing ink of at least one of the printing ink layers comprises at least one pigment and/or at least one dye, which changes its color upon exposition to laser radiation, iii) curing the printing ink layers, iv) exposing the printed and cured (dried) substrate sheet to laser radiation so as to create one or more features selected from the group consisting of individual numbers each comprising at least two numerals and optionally one or more characters, of individual QR codes, of individual barcodes and arbitrary combinations of two or more of the aforementioned features on each banknote of the printed substrate sheet, wherein all of the one or more individual (serial) numbers, of the one or more QR codes and of the one or more barcodes are generated by the exposure to the laser radiation, and v) cutting the printed substrate sheet obtained in step iv) to individual banknotes.