| 摘要 |
<p>The invention teaches a novel paper substrate having a transparent field of a dense array of a plurality of laser-formed microperforations. The resul tant paper can be useful as a replacement for glassine paper, and can be use ful in secure documents. The transparent field is integral to the paper subs trate and can be formed by laser techniques surprisingly resulting in a tran sparent field retaining acceptable strength characteristics after lasing. Th e transparent field acts as a self authentication device.</p> |
