| abstract |
A laser-imageable direct write medium comprising an infrared dye in photoreactive association with a leuco dye, in which irradiation of the medium at a wavelength absorbed by said infrared dye converts said leuco dye to the corresponding dye, characterised in that the said infrared dye comprises a chromophore which is formally the product of a one-electron or two-electron oxidation of a p-phenylenediamine or a 4,4'-biphenylenediamine. |