An authentication method comprises providing at least one object having a print region with printed material contained thereon, the print layer comprising a layer of non-visible indicia. At least a portion of the non-visible indicia is formed from an emitting substance that emits at least one wavelength of light outside a visible range of an electromagnetic spectrum when stimulated with electromagnetic radiation. The non-visible indicia comprises optically encoded indicia. The method further comprises creating an optical image of the layer of non-visible indicia with an imaging device such that the layer of non-visible indicia can be perceived by a human eye viewing the optical image. The method still further comprises decoding the optically encoded authentication indicia and comparing the decoded authentication indicia to expected authentication indicia to verify the authenticity of the object.