| 摘要 |
FIELD: physics, computer engineering.SUBSTANCE: invention relates to a data medium with a printed magnetic protective feature and a method of making such a data medium. The method of making the data medium involves carrying out a first step where a data medium for forming at least part of the protective feature is printed with printing ink which contains a certain amount of a magnetic substance in form of a magnetic paste mixed with the basic ink with para- and/or ferromagnetic particles At the second step, on a least one separate area printed by the printing ink, the amount of the magnetic substance is reduced by removal, respective demagnetisation of at least a portion of the magnetic particles.EFFECT: invention enables to obtain a data medium with a machine-readable protective feature which is impossible to detect visually, thereby providing high protection from counterfeit and falsification.21 cl, 15 dwg |
