Oleophobic coating on mobile phones

All modern mobile devices have a thin glaze of oleophobic coating material covering their screens. 'Oleophobic' describes a type of material, which lacks an affinity to oils.

Oleophobic coating provides a certain amount of finger smudge resistance to your smartphone's display; it doesn't make it fingerprint proof, but keeps the grease at bay, not allowing it to adhere to the glass. This is why a simple wipe with a soft cloth will often leave the smartphone looking brand new, without the use of any extra cleaning solutions. Usually, if any normal glass has fingerprints on it, trying to wipe it with nothing but a cloth will bring much different results – the grease spreads across the surface and just follows the cloth's strokes, without coming off completely – it generally needs some kind of cleaning solution to be completely cleaned off.

The oleophobic layer also has a slightly slippery feel to it, which makes our gadgets feel slick to the touch. This also helps the glass be more scratch resistant, as a reduced friction will cause dangerous materials to slide off the surface, rather than damaging it. Unfortunately the olephobic layer wears off over time. This is dependent on: (1) amount and type of usage, (2) each human's body has varying levels of acidity to their sweat, (3) the method of bonding the coating to the glass, and the type of polymer used. The quality issue is mostly normalized as most manufacturers use Gorilla Glass which comes with its own coating. Generally, an oleophobic coat should last a smartphone's typical 2-year life cycle.

To test whether the coating has worn off, drip a single drop of water on the display. If the drop gathers around itself and stays in an almost spheric form, the surface is fine. If it splats on the display then you have worn-out grease-repeller. A more extreme test (not recommneded on a new or expensive mobile device) would be to pick up a marker and draw a line across the glass. If the oleophobic coating is still there the line will erase itself as the marker's trail breaks up and forms many little dots which can be wiped off the screen. If the coating is gone the line will stay on the glass.

Cleaning your mobile device's glass should be done with a soft, cotton cloth. In extreme cases use water-based solvents.

If your screen has shed its oleophobic coating you can always use a screen protector. The more expensive screen protectors will have an oleophobic coating of their own.