Touchscreens often attract fingerprints. After all, you can’t control a touchscreen without touching it. All touchscreens require direct contact to perform a command, so they’ll inevitably attract fingerprints over time. In some cases, fingerprints are harmless and won’t affect a touchscreen’s functionality. In other cases, they can prevent a touchscreen from registering commands.

How Fingerprints Affect Touchscreen Commands

Fingerprints can prevent a touchscreen from registering your commands by blocking the flow of electricity between the device’s interface and your finger. Most touchscreens use capacitive technology. Known as capacitive touchscreens, they register commands by measuring electricity.

Touching or tapping the interface with a conductive object — a bare finger is considered a conductive object — will change the touchscreen’s electrical charge. If there’s a fingerprint on the touchscreen, though, the electrical charge may fail to change.

Resistive Touchscreens

Resistive touchscreens are less susceptible to the effects of fingerprints. They don’t detect touch commands by measuring electricity. Instead, they work mechanically by using two layers with conductive contacts. Pressing or tapping the interface will force the two layers together so that their conductive contacts touch each other.

Since they work mechanically, resistive touchscreens will register your touch commands even if the interface is covered in fingerprints. Fingerprints can prevent the flow of electricity from a capacitive touchscreen’s interface to your finger. Resistive touchscreens, on the other hand, don’t create a flow of electricity between the interface and your finger. Therefore, they are virtually immune to the effects of fingerprints.

Optical Coatings

Both capacitive and resistive touchscreens are often designed with an optical coating to further protect against fingerprint interference. Also known as an oleophobic coating, it consists of an oil-resistant liquid that’s applied over the interface. Optical coatings are invisible, so you typically won’t see them. Nonetheless, they act as a shield by wicking away oils and protecting against fingerprints.

Because they contain an optical coating, touchscreens shouldn’t be cleaned with any solvents. Many people mistakenly use rubbing alcohol to clean their touchscreens. While rubbing alcohol is an excellent cleaner, it’s an equally powerful solvent. When applied to a touchscreen’s interface, it will degrade the device’s optical coating. And once the optical coating is gone, the touchscreen may no longer offer protection against fingerprint.

Though it’s a minor concern, fingerprints can affect the functionality of some touchscreens. Capacitive touchscreens require direct contact with a conductive object. If a capacitive touchscreen has fingerprints on it, it may fail to register your touch commands. With that said, most capacitive touchscreens have an optical coating to protect against fingerprints.