| 摘要 |
<p>This invention is a process for creating a watermark on a polymeric sheet by (a) passing the sheet between two rollers in abutment with each other, at least one of which bears hollow or in relief motifs so as to form an impression corresponding to the motif on the passing sheet. The impressioned sheet is then oriented by stretching such that the oriented sheet, under transmitted light, exhibits an impression of the motif which is light and dark in areas corresponding respectively to the in relief and the hollow portions of the motif on the roller. The watermarks can be used on documents which need a degree of security such as eg deeds, identity cards, passports and bank notes. <IMAGE></p> |
