Ink compositions containing lanthanide complexes

摘要

Disclosed is an ink composition comprising: (a) a compound of formulae (X), (XI) or (XII); (b) a liquid ink carrier. Optionally further comprising: (c) a binder resin; and optionally further comprising (d) one or more colourants. Further disclosed is a method for providing a hidden mark on an object comprising applying onto said object an ink composition and removing all or substantially all of said ink carrier by evaporation or absorption into said object.