The document discusses anti-counterfeiting filters for currencies, IDs, and goods. It describes existing technologies like barcodes, RFID, and holograms and their limitations. The presented technology uses optically variable devices with interference filters and polymers that change color with viewing angle to provide verification difficult to reproduce. When the filter and polymer are patterned with a logo and their transmission spectra are designed to be metameric, they will closely match colors across viewing angles, serving as effective authentication.