Near Infrared pigments which are mainly transparent in the visible range of the spectra can be used in different application fields:
Glass windows are transparent for visible and infrared light. In hot climate regions it is however not desirable to heat the building additionally by the infrared radiation through the window. An infrared absorbing material on the window can save cooling costs.
Documents or bank notes marked with IR (infrared ink) can be identified only with an specific infrared detector. In opposite to UV (ultraviolet) inspection this is more specific and more difficult to falsify.