A plasticized ultraviolet or electron beam (UV/EB) cationically cured coating, such as a release layer or print from UV/EB cured inks, comprises polymers with a reactive plasticizer incorporated therein. The cured coating contains the plasticizing additives permanently attached to the polymer matrix, locking them in place, and permanently flexibilizing the cured coating. The cured coating finds use on varied substrates including printable substrates used in conventional printers and those with release layers for adhesive labels. Coating formulations which form these cationically cured coatings comprise cationically polymerizable monomers and/or oligomers, a reactive plasticizer which is food grade, cosmetic grade, medical grade or biologically benign when incorporated in the polymer backbone, and a catalyst.