| 摘要 |
<p>Plate has material which takes up colour on surface of engraved part and colour-repellent material on remaining, non-printing surface. This non-printing surface has coating of porous material (e.g. black Cr, Ni phosphide, Al2O3), impregnated with hygroscopic substance (pref. LiCl). Process is esp. useful in printing of bank notes. It is simpler and more economical than usual, since colour repellent coating obviates need for regular wetting agent application during printing.</p> |
