The history of the passport dates back thousands of years, evolving from a single piece of paper into a complex book with multiple pages, allowing us travelers to explore the world how we see fit.

More recently, passports have been redesigned to be more secure and combat identity theft. But do you know how many features are found on the passport, making it difficult to forge? Let’s take a look at the six aspects, some of which you may (or may not) already know of.

Seal

The seal on the cover of a passport is very important in identifying fraud. Every country has its own seal that’s imprinted with foil and plastic onto the front. The fact is, each seal is specifically designed for the country it belongs to, and knowing how to perform foil stamping is challenging and requires a special training skill that not many can attain.

Print

Printing a passport is not as simple as one may think—it calls for a special type of machine that can produce color resolutions more advanced than any printer available to the public. And some of the pages’ components, when printed, can only be seen through a microscope (it’s that miniscule).

Biometrics

Most passports nowadays are biometric, which means they have a small chip inside that contains important information such as the passport number, date of birth, name, place of birth and other information found on the interior photo-page spread. This provides another coat of safety.

Just like foil stamping, duplicating a chip is hard and requires a lot of expensive technology, which is why 90 percent of the world’s countries have adapted biometrics.

Holograms

If you open up your passport, you will notice holograms throughout the photo-page spread. These are extremely important, and almost every country uses them,. Plus, each nation has their own design and specialty ink that goes over the hologram. The good thing is these are almost impossible to replicate.

Inks

The ink you will see inside your passport varies in color, and can also appear to be different colors depending on which angle and which direction the light is coming from. Some countries print the ink in a photographic way. For instance, the Finnish passport has a photo of a moose that, when flipped, looks as though he’s taking a stroll. Canada’s passport pages have “pop-outs” of elements (when looked under a special light) found in the country such as a star-filled sky, geese, maple leaves and more.

On a different level, the US passport has inks that can alter in color if it comes into contact with extreme temperatures, or disappear completely if it’s messed with.

Fonts

A common theme you must be picking up on (or may have already known), is that each nation has its own, very particular elements found on and within their passports. This also includes the font, which is top secret, and thus very hard to replicate unless you have access to the typeface.