Process for blending of ink used in counterfeit detection systems

In the method for associating source information with a substrate, which includes providing at least one latent marking agent that emits a signal at an emission wavelength in response to being irradiated with infrared radiation at an excitation wavelength, wherein the signal is at least a portion of the source information; and affixing the at least one latent marking agent to the substrate, a process for providing an ink with a viscosity for effective printing of the source information on the substrate. The at least one latent marking agent includes an inorganic pigment. In some embodiments of the method, the latent marking agent must be exposed to ultraviolet radiation before it can emit a signal in response to infrared irradiation.