Here’s The Surprising Answer To What Airline Windows Are Actually Made Of

Though you may not realize it, airplane windows are a marvel of engineering. And no, they’re not actually made of glass.

Unless you’re an aviation geek, you probably don’t know that plane windows are actually composed of three separate parts. The outer layer of the window is flush with the fuselage, while the middle pane is the part with the tiny hole in it. When you’re inside the plane, you actually can only touch the third inner layer called the “scratch pane.”

So what are plane windows made of? They’re actually designed out of something called “stretched acrylic.” This material is lightweight, durable, and can stand up to the vibration and pressure caused by flight.

Interestingly, the inner scratch plane of a window isn’t actually air-tight. There are gaps along the interior wall of the plane that allow some air to flow between the inner and middle sections of the window in order to help equalize pressure.

The next time you have the window seat, be sure to thank clever engineering for your view.