| 摘要 |
A substrate for security documents such as banknotes, cheques and passports which are required to provide a high degree of security against imitation comprises at least a plurality of layers (14,15) of polymeric film laminated together with at least one metallic layer (17) therebetween, wherein at least one of the polymeric layers (14) is biaxially oriented and at least another (15) comprises an opaque voided film wherein the opacity of at least a portion of the voided polymeric layer is reduced. The metallic layer (18) may be partially demetallised. |
