The invention relates to a security sheet or document having enhanced watermark(s). In one exemplary embodiment, the inventive security sheet or document is a single-ply paper that is made up of a paper layer including one or more watermarks, and a micro-optic security device (e.g., a patch or thread) that at least partially covers an upper or face portion of the watermark(s). The overlying patch or thread increases the durability of the watermark(s), thereby allowing for the watermark(s) as well as reduced fiber density areas therein to be made larger, and for the reduced fiber density areas to be made thinner. In a preferred embodiment, the micro-optic security device projects synthetic image(s) that coordinate or link in with the watermark design(s). In a more preferred embodiment, the micro-optic security device offers a machine detectable/readable feature in the form of enhanced IR-brightness, especially when measured in transmission.

Methods for product authentication, which include: applying an analyte encoded security fluid to a substrate of the product; obtaining a sample of the fluid from the substrate; and testing the sample for the presence of the analyte.

Methods for product authentication, which include: applying an analyte encoded security fluid to a substrate of the product; obtaining a sample of the fluid from the substrate; and testing the sample for the presence of the analyte.

The invention includes a radiation diffracting member having a crystalline structure comprising an ordered periodic array of hollow particles. The radiation diffracting member also includes a matrix material in which the array of particles is received.

The invention includes a radiation diffracting member having a crystalline structure comprising an ordered periodic array of hollow particles. The radiation diffracting member also includes a matrix material in which the array of particles is received.

Embodiments include articles, authentication methods and apparatus, and article manufacturing methods. An article includes a substrate with a first luminescent taggant, and an extrinsic feature with a second luminescent taggant, which is positioned proximate a portion of the article surface. The first and second taggants produce emissions in overlapping emission bands as a result of exposure to excitation energy. Above the extrinsic feature, the substrate and extrinsic feature emissions combine in the overlapping emission band to produce confounded emissions that are distinguishable from the substrate emissions taken alone. An authentication system determines whether, in a region corresponding to a substrate-only region of an authentic article, emissions having first emission characteristics are detected in the overlapping emission band. The system also determines whether, in a region corresponding to an extrinsic feature region of an authentic article, the confounded emissions are detected in the overlapping emission band.

Embodiments include articles, authentication methods and apparatus, and article manufacturing methods. An article includes a substrate with a first luminescent taggant, and an extrinsic feature with a second luminescent taggant, which is positioned proximate a portion of the article surface. The first and second taggants produce emissions in overlapping emission bands as a result of exposure to excitation energy. Above the extrinsic feature, the substrate and extrinsic feature emissions combine in the overlapping emission band to produce confounded emissions that are distinguishable from the substrate emissions taken alone. An authentication system determines whether, in a region corresponding to a substrate-only region of an authentic article, emissions having first emission characteristics are detected in the overlapping emission band. The system also determines whether, in a region corresponding to an extrinsic feature region of an authentic article, the confounded emissions are detected in the overlapping emission band.

A security element for securing value documents comprises a first polymer containing a feature substance, which is at least partially surrounded by a second polymer, wherein the first polymer is a hydrophobic, water-insoluble polymer which, at an elevated pH value and at elevated ambient temperature at a treatment duration of less than 60 minutes can be converted into a hydrophilic, water-soluble polymer. The security elements also contains a second polymer, which is a hydrophilic, water-soluble polymer, wherein the elevated pH value is greater than 12 and the elevated ambient temperature is greater than 90 C.

A security element for securing value documents comprises a first polymer containing a feature substance, which is at least partially surrounded by a second polymer, wherein the first polymer is a hydrophobic, water-insoluble polymer which, at an elevated pH value and at elevated ambient temperature at a treatment duration of less than 60 minutes can be converted into a hydrophilic, water-soluble polymer. The security elements also contains a second polymer, which is a hydrophilic, water-soluble polymer, wherein the elevated pH value is greater than 12 and the elevated ambient temperature is greater than 90 C.

An optical security feature has pixels with faceted microstructures supporting nano-patterned optical filters. Each of the pixels includes a substrate and a nanostructure. The substrate is configured to emit light of at least a first wavelength and a second wavelength different than the first wavelength. The microstructure includes a first facet, a second facet non-parallel to the first facet, a first nano-patterned optical filter disposed on the first facet, and a second nano-patterned optical filter disposed on the second facet. The first nano-patterned optical filter includes a first stopband that includes the first wavelength and excludes the second wavelength. The second nano-patterned optical filter includes a second stopband that includes the second wavelength and excludes the first wavelength. For each pixel, the first nano-patterned optical filter inhibits emission of light at the first wavelength from the pixel via the first facet.