Abstract: An improved ink suitable for ink jet printing comprising, a mixture of a colorant, an arylketoalkene stabilizing compound or a photoreactor, and a liquid vehicle, wherein the colorant is light-stable. When the photoreactor is combined with a wavelength-selective sensitizer to form a radiation transorber, the colorant is mutable upon exposure of the radiation transorber to specific, narrow bandwidth radiation. The colored composition may also contain a molecular includant having a chemical structure which defines at least one cavity wherein each of the colorant and photoreactor or radiation transorber is associated with the molecular includant. The invention also includes ink jet print cartridges containing the improved ink, ink jet printers containing the improved ink and methods of printing using the improved ink.