Abstract: A method of forming an image on a substrate by applying energy, involves a substrate in or on which there are at least two different colour-change agents, i.e. a first colour-change agent capable of giving rise to at least two different colours; and a second colour-change agent capable of giving rise to at least one different colour than achievable with the first colour change agent. A preferred embodiment of the invention is a multi-layer laminate comprising, in order, a layer comprising the first agent, a barrier layer, and a layer comprising the second agent.

Abstract: A method of forming an image on a substrate by applying energy, involves a substrate in or on which there are at least two different colour-change agents, i.e. a first colour-change agent capable of giving rise to at least two different colours; and a second colour-change agent capable of giving rise to at least one different colour than achievable with the first colour change agent. A preferred embodiment of the invention is a multi-layer laminate comprising, in order, a layer comprising the first agent, a barrier layer, and a layer comprising the second agent.

Abstract: A method of forming an image on a substrate by applying energy, involves a substrate in or on which there are at least two different color-change agents, i.e. a first color-change agent capable of giving rise to at least two different colors; and a second color-change agent capable of giving rise to at least one different color than achievable with the first color change agent. A preferred embodiment of the invention is a multi-layer laminate comprising, in order, a layer comprising the first agent, a barrier layer, and a layer comprising the second agent.

Abstract: A method of forming an image on a substrate by applying energy, involves a substrate in or on which there are at least two different colour-change agents, i.e. a first colour-change agent capable of giving rise to at least two different colours; and a second colour-change agent capable of giving rise to at least one different colour than achievable with the first colour change agent. A preferred embodiment of the invention is a multi-layer laminate comprising, in order, a layer comprising the first agent, a barrier layer, and a layer comprising the second agent.

Abstract: The invention relates to use of a diacetylene compound as a color former wherein the diacetylene compound has one of general formulae (I) to (V). The invention also includes methods of imparting color to a material including a compound as defined above, which comprises subjecting the material to irradiation.

Abstract: A tape construct comprises a laser-imageable composition, whereby images can be created in said tape by irradiation with a laser. In an alternative, a laser-imageable formulation suitable for spray application to a substrate, comprises a color-former, a binder and a carrier.

Abstract: A colorless or transparent composition comprises a charge-delocalization compound and a photoacid, wherein the photoacid generates an acid on irradiation or heating, thereby forming a colored change-transfer complex with said compound.

Abstract: The invention relates to use of a diacetylene compound as a colour former wherein the diacetylene compound has one of general formulae (I) to (V). The invention also includes methods of imparting colour to a material including a compound as defined above, which comprises subjecting the material to irradiation.

Abstract: A colourless or transparent composition comprises a charge-delocalisation compound and a photoacid, wherein the photoacid generates an acid on irradiation or heating, thereby forming a coloured change-transfer complex with said compound.

Abstract: A method of ink-less printing comprises the steps of: providing a source (1) for emitting an energy beam,—providing an array of programmable shutters (3), each adapted for selectively blocking or allowing passage of at least some of an energy beam therethrough; providing a substrate (4) including an additive susceptible to changing colour when energized by the energy beam emitted by the source; selectively allowing passage of at least some of the energy beam emitted by the source through the array of shutters; and, positioning the substrate in the path of the energy beam that has passed through the array of shutters such that at least one desired point on the substrate is energized by said beam thus causing the additive to change colour at said point.

Abstract: A tape construct comprises a laser-imageable composition, whereby images can be created in said tape by irradiation with a laser. In an alternative, a laser-imageable formulation suitable for spray application to a substrate, comprises a colour-former, a binder and a carrier.

Abstract: A method for forming an image on a substrate, which comprises applying to the substrate a combination of a diacetylene and a photoacid or photobase, and polymerising the diacetylene by radiation, is provided. The method finds use in multi-colour printing.