Method for laser-marking a document, the document showing a fixed colour in a surrounding with a colour shift effect

摘要

Document comprising a coating containing at least one sort of effect pigments and at least one sort of laser sensitive pigments, wherein said document also comprises at least one laser mark having one colour of the effect pigment fixed in a surrounding with a colour shift effect. Said document is obtainable by a process, wherein a document comprising a coating containing at least one sort of effect pigments which show different colours under different viewing angles and at least one sort of laser sensitive pigments is treated on at least a part of the coated area with a laser beam operated in cw mode at a rate within the range of 500 mm/s to 2000 mm/s using a power within the range of 60 % to 100 %. The authenticity of the document can be easily checked by visual inspection from different viewing angles.