Hologram
A diffractive optically variable device. Optical properties of the hologram are defined in terms of diffraction of light going through a diffraction grating. Optical effects occur when changing the angle of observation or illumination. Holograms may contain nano-, microprinting, microimages, covert laser readable images, etc.
Classification of holograms by optical properties:
- Reflection holograms form an image in reflected light. Aluminum foil or a transparent dielectric which reflects not more than 10-20% of light (transparent hologram) are used as a reflection layer.
- Transmission holograms form an image in transmitted light.
KINEGRAM® is a patented solution produced by the Swiss manufacturer OVD Kinegram and used for protection of security documents and banknotes.
![Romania. Temporary passport issued in 2016: page 2](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/1l.webp)
a
![Romania. Temporary passport issued in 2016: the same. Holograms over the whole document page](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/2l.webp)
b
![Romania. Temporary passport issued in 2016: the same. Diffractive identification device DID® (lower frame, fig. 1b)](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/3l.webp)
c
![Romania. Temporary passport issued in 2016: the same. Microtext (upper frame, fig. 1b)](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/4l.webp)
d
Fig. 1. Romania. Temporary passport issued in 2016:
a — page 2; b — the same. Holograms over the whole document page; c — the same. Diffractive identification device DID® (lower frame, fig. 1b); d — the same. Microtext (upper frame, fig. 1b)
![Iraq. Special passport issued in 2011: page 3](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/5l.webp)
a
![Iraq. Special passport issued in 2011: the same. Zoomed fragment. View at different angles of observation](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/6l.webp)
b
![Iraq. Special passport issued in 2011: the same. Zoomed fragment. View at different angles of observation](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/7l.webp)
c
![Iraq. Special passport issued in 2011: the same. Zoomed fragment. View at different angles of observation](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/8l.webp)
d
Fig. 2. Iraq. Special passport issued in 2011:
a — page 3; b, c, d — the same. Zoomed fragment. View at different angles of observation
![Great Britain. Visa issued in 2004: visa in the form of a sticker](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/9l.webp)
a
![Great Britain. Visa issued in 2004: the same. KINEGRAM®. View at different angles of observation](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/10l.webp)
b
![Great Britain. Visa issued in 2004: the same. KINEGRAM®. View at different angles of observation](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/11l.webp)
c
![Great Britain. Visa issued in 2004: the same. Nanotext (zoomed fragment of the letter K)](https://static-content.regulaforensics.com/Hardware-products/knowledge_hub/glossary_documents/HOLOGRAM/12l.webp)
d
Fig. 3. Great Britain. Visa issued in 2004:
a — visa in the form of a sticker; b, c — the same. KINEGRAM®. View at different angles of observation; d — the same. Nanotext (zoomed fragment of the letter K)