Engraving process giving translucent polychromatic images - esp. used in colour printing

摘要

A polychromatic translucent image is obtd by an engraving process using several translucent monochromatic supports, usually films. Each support is a transparent material e.g. polyethylene glycol terephthalate or an acetate, coated on one surface with a layer of coloured material which is selectively removed by a scraping or erasing engraving tool to give a design corresponding to the final image. The engraved monochromatic supports are superimposed to give, by transparency, the polychromatic image. The engraving is carried out when the monochromatic sheet is placed on a luminous surface, possibly on top of other monochromatic sheets. A transparent sheet on which is traced a sketch for use a model can be placed between the sheet and the luminous surface, and adjusted if necessary w.r.t. other intermediate monochromatic sheets. A variety of colour combinations can be produced in the translucent polychromatic image, for use partic. colour printing.