Laser Perforation
Laser perforation forms an image by burning a pattern of microscopic holes clean through a document — usually the document number, sometimes a duplicate of the holder’s portrait. Held against a light, the holes glow and the image appears. Viewed normally, they are barely visible.
| Also called | Perforated number, photo perforation, laser image perforation |
| Mechanism | Microscopic holes burned entirely through the substrate |
| Hole shape | Conical — wider on the entry side, narrower on the exit |
| Typical image | The document number; on some passports, the portrait |
| How to check | Hold against a light source and look through |
| Applied to | Passport pages and data pages, in a single pass |
| Personalized | Yes — it carries data unique to the holder |
Why the taper is the security feature
The holes are not cylindrical. A laser burning through a substrate removes more material where it enters than where it exits, so each hole is a cone: wider on one face, narrower on the other.
That asymmetry is the part that resists imitation. Mechanical punching produces holes of roughly equal diameter on both sides. Drilling from one side produces a taper, but reproducing the specific cone angle, the hole spacing, and the clean edges of a laser burn across hundreds of holes in an exact pattern is a different order of difficulty.
The taper also means the feature looks different from each side, which is a check available to anyone who turns the page over. And because the holes go entirely through the substrate, the pattern appears on every layer it passes — a perforated number burned through a passport’s pages is present, and aligned, on all of them.
That alignment matters. It proves the pages were assembled before the perforation was applied, which means an added or substituted page will not carry the pattern in register with the rest.
Why laser perforation matters for identity verification
It is one of the few security features that is both personalized and structural. Most personalized elements are printed or engraved onto a surface; most structural features are generic to the document design. Perforation is both: the number is unique to the holder, and it exists as physical absence of material rather than as anything added.
You cannot alter it by removing something, because there is nothing there to remove. Filling the holes to change a digit leaves the fill visible against transmitted light.
The operational catch is the same one that applies to watermarks and security threads: it requires light passing through the document. A capture flow that photographs a page lying flat on a table cannot see it at all. Reaching it remotely means asking the holder to backlight the page, which is a different instruction from “photograph your passport” and is not always practical — a real constraint on what a remote identity document verification check can honestly claim to have verified.
What to look for
| Check | Genuine | Imitation |
|---|---|---|
| Against a light | Clean, bright, evenly sized points | Ragged, uneven, or partly blocked |
| Hole shape | Conical — different diameter each side | Often equal on both sides |
| Across pages | Present and aligned on every page it passes | Misaligned, or on one page only |
| Data match | Matches the printed document number | Mismatch, or an altered digit |
| Surface feel | Slight roughness on the exit side | Smooth, or burred from punching |
What laser perforation can’t do
It needs transmitted light. Without a backlight there is effectively nothing to see, which rules it out of most standard remote capture.
It is not on every document. Common on European passports, far less so elsewhere and rare on cards. Absence means nothing unless you know the design should have it.
Damage confuses it. A well-used passport accumulates wear that can obscure or distort the pattern, so an unclear result on an old document is weak evidence.
It proves the artifact, not the person. A perfectly executed perforation confirms the document was produced and assembled properly. Whether the holder owns it is answered by liveness detection and biometric matching.
Frequently asked questions
How do you check laser perforation?
Hold the page up to a light and look through it. The holes should form a clean, legible image — usually the document number — with evenly sized bright points. Then check that it matches the printed number and that it appears aligned on the pages it passes through.
Why are the holes cone-shaped?
A laser removes more material where it enters than where it exits, so each hole tapers. That asymmetry is difficult to reproduce by punching or mechanical drilling and gives a check available from either side of the page.
Do all passports have laser perforation?
No. It is common on European passports and much less so elsewhere, and it is rare on ID cards. Its absence is only meaningful if you know that particular design should carry it.
Can laser perforation be altered?
Not by removal, since the feature is absence of material rather than anything added. Filling holes to change a digit leaves the fill clearly visible when the page is held to a light.
