A security thread—a polymer or metallic stripe embedded in paper—appears in modern passports in two main types: latent, which is fully embedded within the paper, and diving, which is partially exposed on the surface.
Additionally, security threads can incorporate extra passport security features to enhance protection such as microprinting, images that have ultraviolet luminescence and infrared visibility, presence of dynamic images based on micro-optical technologies, etc. Variations of these elements in security threads result in a wide range of unique designs that are worth a closer look.
In this article, we’ll examine security threads in passports, their unique features, and how they’re authenticated.
Worth your attention: Check out A Common Thread is a Security Thread: Exploring Their Variety in Banknotes, where we explain in detail the classification of security threads, their prominent features and how they are used in banknotes. The same principles are true for security threads in passports.
We’ll deliver hand-picked content from Regula’s experts into your inbox
Examples of security threads in passports
Now, let’s take a look at a selection of passports that, in our opinion, best showcase the variety of security threads used in travel documents.
1. Spanish passport, 2015
Spanish passport issued in 2015 which contains a latent security thread that is more than 5 mm in width. It features a dotted pattern luminescent under UV light and the same visible pattern with additional elements under IR light.
The zoomed part of the Spanish passport in transmitted light
2. Sudanese passport, 2008
Passport of Sudan. It features a latent security thread. The flag is printed with dyes that display differently in 870 and 940 nm infrared light. The name of the country “SUDAN” is printed with demetallization technique.
3. Uzbek passport, 2019
Passport of Uzbekistan issued in 2019. It features a diving metallic security thread.
The zoomed fragment of a diving security thread. Under transmitted light, the diving thread appears solid with distinctive alterations of paper pulp density.
4. Norwegian passport, 2020
Passport of Norway issued in 2020. It features a diving security thread that glows under ultraviolet light and remains visible under infrared light.
Zoomed fragments of a diving security thread showing a characteristic torn edge and visible paper fibers at the points where the thread “dives in” and “dives out.”
5. Swedish passport, 2022
Passport of Sweden issued in 2022. The diving security thread features a floating effect.
Visualization of the floating effect which is based on micro-optical technology
6. Vietnamese passport, 2023
Passport of Vietnam issued in 2023. The data page features a security thread that glows under ultraviolet light and has microtext.
The zoomed microtext
7. Kyrgyz passport, 2024
Passport of Kyrgyzstan issued in 2024. It features a diving security thread with a holographic effect.
Visualization of holographic effect
8. Latvian passport, 2024
Passport of Latvia issued in 2024. It features a diving security thread with a color-changing effect.
Visualization of color-changing effect
If you are interested in learning more about the Latvian passport, don’t hesitate to read Top-Notch ID Document Processing Worldwide: Latvia
How to authenticate security threads in passports
Security threads can incorporate a variety of additional passport security features, including color-changing and luminescent elements, holograms, and microtext—each of which can be examined for authenticity. That’s why, beyond using basic transmitted light, it is beneficial to have multiple magnification levels and varied light sources for thorough verification.
The Front-line Border Control Device Regula 4205D is an ideal solution for conducting comprehensive passport authenticity checks, including the examination of embedded security threads. It features multiple types and wavelengths of white, ultraviolet, and infrared light, up to 30x on-screen zoom, and built-in MRZ, RFID, and barcode readers.
However, simply detecting, visualizing, and capturing these features is not always enough. To determine whether a passport is genuine or if its security features have been imitated, a comparison with a reference sample is essential.
The Regula 4205D can be equipped with Information Reference Systems—a digital catalog of documents and banknotes containing detailed images of passport pages, along with close-ups of security features under different light sources. This catalog is regularly updated and includes both current and obsolete documents and banknotes, ensuring accurate and reliable verification.
The interface of the operating program can be divided into halves for comfortable comparison.
Examination of Moldavian passport. The above half of the screen is a reference image from the Information Reference Systems. The below half is the video from the camera
If you’re in doubt, don’t hesitate to contact us for a complete consultation on Regula solutions.
