Coding system for value documents

摘要

The invention relates to a composition for coding having at least one pair of mutually associated luminescent substances having first and second luminescent substances which emit in a joint emission range located outside the visible spectral range. The emission spectra of the first and second luminescent substances overlap in at least a subrange of the stated emission range such that the emission spectrum of the first luminescent substance is complemented by the emission spectrum of the second luminescent substance.