SHEET WITH LOW-OPACITY AREA PROTECTED AGAINST COPYING Russian patent published in 2008 - IPC B42D15/00 

FIELD: polygraphy.

SUBSTANCE: typography paper protected against imitation contains an area to receive printed characters on both sheet sides, the printed characters seen in reflected light and forming the image observed in transmitted light. The said area serves as protective element ruling out double-side copying. It is also a screened area with a mean opacity lower than that of the vellum paper part and is composed of alternating mini-sections of approximately constant thickness equal to that of the vellum area of the remaining paper and mini-sections of lower opacity provided by their smaller thickness compared with that of the vellum paper part. The characters form the drawings seen in reflected light, the latter being made so that they form a final image seen in transmitted light. A bank note is also proposed made from the paper protected against imitation. The paper has been produced allowing examination of dual-surface complex and fine printed characters ruling out their imitation, provision of sufficient mechanical paper properties and a large-size area for printing characters.

EFFECT: protection against dual-surface copying by characters on both sheet sides.

21 cl