Start with the power off
Not just for safety. A dark screen shows dust clearly, and you are less likely to press hard on a lit module. Wait five minutes after power off so the surface is at room temperature.
Dry first, always
A dry microfibre cloth removes most dust. Work from the top down in straight passes, not circles. Circular motion on a matte mask leaves a visible polish pattern under raking light.
If it needs moisture
Use distilled water on a microfibre cloth, wrung almost dry. Never spray directly on the screen. Never use tap water in a hard-water area, because the minerals leave a film that attracts more dust.
What never to use
- Paper towels: wood fibre scratches the mask.
- Glass cleaner with ammonia: attacks the anti-glare coating.
- Compressed air cans: propellant can spit and leave a permanent stain.
- A vacuum brush attachment: static and bristles both damage modules.
Outdoor screens
Hose at low pressure from the top down, then a soft brush on a pole for the stubborn line at the bottom. Never pressure-wash. Water at 100 bar will push past the module gasket. Do it in the morning so the screen dries before the heat of the day, which prevents water spots.
How often
Indoor: every two weeks in a lobby, every month in a clean office. Outdoor: every two weeks in a dusty city, monthly in a clean one. The bottom row always needs more attention because dust settles there.
The habit that prevents damage
Keep a dedicated cloth in a sealed bag near the screen, and put a small sign on the service hatch saying which cloth. The damage usually comes from someone improvising with a paper towel because the right cloth was not there.