A laminated construct such as a ticket or game piece includes an internal on-demand thermally printable layer hidden between substantially opaque substrates. One of the substrates is a metallized film and the other substrate is a direct thermal print medium. The construct can be arranged in various ways including an arrangement for presenting some thermally printed information for immediate viewing and other thermally printed information that is temporarily hidden from view beneath the metallized film. The arrangements include arranging the metallized film as a plurality of island that are individually peelable apart from the direct thermal print medium for revealing the temporarily hidden information.

The invention is directed towards a composition comprising: a near-infrared radiation absorbing compound; a colour-forming compound; and a heat transfer agent operable to facilitate heat transfer from the near-infrared radiation absorbing compound to the colour-forming compound; wherein the near-infrared radiation absorbing compound is present in an amount of 0.1-3.5 wt % of the total composition, and the heat transfer agent is present in an amount of 1-15 wt % of the total composition, and the heat transfer agent is present in the composition as solid particles. The invention further relates to substrates comprising the composition applied thereto, as well as methods of forming colour or an image on said substrates.

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.

A laser marking system (10) comprises a marking controller (11) operable to control a plurality of laser diodes (13) to emit light through optical fibre (14) such that the emitting, ends of the optical fibres (14) form a multi-emitter array. Light emitted from the emitting ends of the optical fibres (14) is focussed by a lensing arrangement (15) on a substrate (16). The lensing arrangement (15) is substantially telecentric such that the non-telecentric angle, θ.sub.t, of the telecentric lens assembly satisfies (Formula I) where θ.sub.1/2 is the half angle divergence of the emitter beam and 1/F is the fraction of the emitter spot diameter d.sub.o that corresponds to the maximum acceptable displacement in the image plane.

An approach for forming a multi-colored image on a substrate that includes a thermochromic material capable of producing at least two different colors is disclosed. Individually selected pixels of the thermochromic material that correspond to the image are heated to predetermined temperatures. Each predetermined temperature corresponds to a predetermined color shift of the thermochromic material. While the individually selected pixels are being heated, an area that includes the individually selected pixels is flooded with an amount of UV radiation sufficient to at least partially polymerize the thermochromic material. A color of each individually selected pixel is determined by a predetermined temperature to which the pixel is heated and the amount of UV radiation to which the pixel is exposed.

A method of forming a multi-colored image on a substrate that includes a thermochromic material capable of producing at least two different colors is disclosed. The method includes heating individually selected pixels of the thermochromic material that correspond to the image to one or more first temperatures sufficient to activate the selected pixels of the thermochromic material for color shift. The area corresponding to the individually selected pixels is flooded with a first UV radiation dosage sufficient to at least partially polymerize the thermochromic material. The individually selected pixels are heated to one or more second temperatures while the area is flooded with a second UV radiation dosage.

A method of imparting color to a plastic substrate comprising applying to the substrate, or incorporating within the substrate, a diacetylene compound of general formula (I) wherein n=1 to 20; R.sup.1=an optionally substituted C.sub.1-20 alkyl group which may contain heteroatoms; T=H, an optionally substituted C.sub.1-20 alkyl group which may contain heteroatoms or (CH.sub.2).sub.mC(O)-Q.sup.2R.sup.2; Q.sup.1=NH, CO, NHCONH, OCONH, COS, NHCSNH or NR.sup.3, wherein m, Q.sup.2 and R.sup.2 are independently selected from the same groups as n, Q.sup.1 and R.sup.1 respectively; R.sup.3 is an optionally substituted C.sub.1-20 alkyl group which may contain heteroatoms; and irradiating the substrate to impart color to the substrate is described.

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.

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.

The invention is directed towards a composition comprising: a near-infrared radiation absorbing compound; a colour-forming compound; and a heat transfer agent operable to facilitate heat transfer from the near-infrared radiation absorbing compound to the colour-forming compound; wherein the near-infrared radiation absorbing compound is present in an amount of 0.1-3.5 wt % of the total composition, and the heat transfer agent is present in an amount of 1-15 wt % of the total composition, and the heat transfer agent is present in the composition as solid particles. The invention further relates to substrates comprising the composition applied thereto, as well as methods of forming colour or an image on said substrates.