Capacitive has become the world’s most popular touchscreen technology. From consumer smartphones and tablets to kiosks and human machine interfaces (HMIs), it’s used in countless touchscreen devices. Capacitive touchscreens are designed to detect touch commands by measuring changes in capacitance. Touching the display interface with a conductive object will change its capacitance. The capacitive touchscreen will then register your touch command.

The top layer, however, is where the magic happens. When you touch the top layer, the capacitive touchscreen will respond. Here are five facts about the top layer of capacitive touchscreens that you probably didn’t know.

#1) Made of Glass

All touchscreens have a top layer. While some of them have a plastic top layer, capacitive touchscreens have a glass top layer. The top layer of a typical capacitive touchscreen is made entirely of glass. Glass is a transparent material with excellent optical clarity. This allows capacitive touchscreens to produce high-quality images.

#2) Coated in ITO

You may not be to see it, but the top layer is coated in indium tin oxide (ITO). Capacitive touchscreens feature a glass top layer, which is coated in a combination of indium, tin and oxide. Known as ITO, this mixture allows capacitive touchscreens to sense touches performed with a conductive object. Plain glass isn’t conductive. ITO, on the other hand, is conductive. With an ITO coating, the glass top layer essentially becomes conductive.

#3) No Pressure Required

The top layer doesn’t require any pressure. You can perform touch commands simply by placing your finger — or any conductive object — against the top layer. As long as a conductive object is touching the top layer, the capacitive touchscreen will register your touch command.

#4) Features an Oleophobic Coating

In addition to ITO, most capacitive touchscreens feature an oleophobic coating. Oleophobic coatings are transparent, oil-repelling coatings. They are designed to protect touchscreens from fingerprints and smudges. You should still clean the top layer using a microfiber cloth. As long as it has an oleophobic coating, though, it will repel oils while promoting a clean, fingerprint-free interface.

#5) Strong and Durable

Some people assume that capacitive touchscreens have a delicate top layer. After all, the top layer is made of glass, and glass can shatter or crack when exposed to mechanical stress. But most capacitive touchscreens use a special type of glass for the top layer. This special glass is strong and durable so that it doesn’t shatter.