Signature protected photosensitive optically variable (POV) inks are provided, which are capable of providing a unique signature in addition to other security features of POV inks. The inks contain at least two types of colorants, and a third, signature component and other ingredients to enable printing. A first colorant comprises a fluorescent dye and/or pigment emitting light within a characteristic emission band when excited by fluorescent-exciting radiation. A second colorant comprises a dye and/or pigment having a light absorption band at overlapping or longer wavelengths than the characteristic emission band of the first colorant in such a way as to result in a dark color. The third component is a fluorescent/phosphorescent rare earth composition. The inks give dark visible ink images, which also produce detectable coincident fluorescent and phosphorescent images. The inks can be used with detectors of red phosphorescence to achieve a new level of security in high speed sorting operations.