| 摘要 |
The invention relates to a sheet (1) comprising a fibrous substrate (2) and at least eon ribbon (3) defining at least one zone of reduced opacity (4), the sheet (1) having at least two complementary security elements (5, 6) situated respectively to either side of said at least one ribbon (3) the whole of which may be transparently viewed due to the zone of reduced opacity (4). |
