Optical principle
Diffractive structures redirect light into controlled images or color changes. They are different from ordinary metallic printing.
Integration
The optical layer is carried in an overlay or laminate and bonded over the credential with controlled clarity and registration.
Inspection value
A well-designed original feature gives inspectors a repeatable visual cue and can make surface replacement or alteration more apparent.
Scope note
This guide covers legitimate material selection and credential manufacturing principles. It does not describe how to copy or bypass the security of any real government credential.
Related materials and technologies
Continue with driver license card materials, overlay films, the security features overview, or the security technology library.