Forgery preventive sheet and method of manufacturing same

A method of making anti-falsification paper with a cylinder paper machine having a plurality of vats, said method comprising:

• forming an inner paper layer in a vat disposed in front of a final vat;
• forming, in the final vat, an outermost paper layer having window portions arranged at intervals along a longitudinal direction of said outermost paper layer;
• forming watermarks in said window portions;
• inserting a thread between said outermost paper layer and said inner paper layer so that said thread is exposed through said window portions of said outermost paper layer, wherein said windows extend laterally beyond longitudinal edges of said thread;
• and
• putting together said outermost paper layer and said inner paper layer, after inserting said thread, to form combination paper having at least two paper layers including said outermost layer and said inner layer, wherein said watermarks are formed in said window portions of said outermost paper layer and said thread is exposed at said window portions.

A method of making anti-falsification paper using a cylinder paper machine having a plurality of vats, said method comprising:

• forming an outermost paper layer in a first vat which is disposed in front of a second vat, said outermost paper layer including window portions arranged at intervals along a longitudinal direction of said outermost paper layer;
• forming watermarks in said window portions of said outermost paper layer;
• forming an inner paper layer in said second vat after forming said outermost paper layer;
• inserting a thread between said outermost paper layer and said inner paper layer such that said thread is exposed through said window portions of said outermost paper layer;
• and
• putting together said outermost paper layer and said inner paper layer, after inserting said thread, to form combination paper having at least two paper layers including said outermost and said inner layers, wherein said watermarks are formed in said window portions of said outermost paper layer and said thread is exposed at said window portions.