METHOD FOR MARKING A FEATURE SUBSTANCE, SECURITY FEATURE, DOCUMENT OF VALUE AND METHOD FOR VERIFYING SAID DOCUMENT

摘要

The invention relates to a method for marking a feature substance, more particularly a feature substance present in powder form, with at least one marker, the feature substance being suitable for authenticating documents of value, comprising the step of mixing the feature substance with a small amount of the marker in particle form, so that the macroscopic detectability of the feature substance is unaffected by the marker and the marker is detectable in a document of value bearing a security feature comprising the marked feature substance through a spatially resolving analytical technique able to resolve down to single-particle level.