In industrial HMIs, EV chargers, access control systems, and biometric terminals, engineers selecting projected capacitive touchscreens (PCAP) often face a recurring question beyond display size, resolution, interface, and brightness:
Is surface treatment necessary for every project? What surface treatment should be applied to the cover glass—AG, AR, or AF? Which option is most suitable, and can multiple treatments be combined?
This article provides a practical comparison of AG (Anti-Glare), AR (Anti-Reflection), and AF (Anti-Fingerprint) treatments, together with selection guidance for common application scenarios. It can help engineers make faster, more confident decisions during project kick-off and sample evaluation.
| Treatment | Main Purpose | Suitable Applications |
|---|---|---|
| AG — Anti-Glare | Reduces glare by diffusing reflected light | Outdoor displays, industrial HMIs |
| AR — Anti-Reflection | Reduces surface reflection while keeping the image clear | Medical devices, precision instruments |
| AF — Anti-Fingerprint | Reduces fingerprints and makes cleaning easier | Kiosks, control panels, frequent-touch devices |
AG / AR / AF coatings are applied on the cover glass of the PCAP touchscreen to improve these aspects and enhance overall HMI performance.
AG stands for anti-glare.
An AG treatment creates a fine matte texture on the touchscreen surface. Instead of reflecting light directly like a mirror, the surface diffuses the reflected light in different directions. This makes bright lamps, windows and surrounding objects less visible on the screen.
AG glass is often used for an anti-glare touchscreen installed in factories, outdoor terminals, control panels and other environments with strong ambient light.
For example, an operator using an industrial HMI under overhead lighting may find it difficult to read a glossy screen. An AG surface can reduce distracting reflections and make the information easier to view.
However, stronger AG treatment is not always better. A very high haze level may slightly reduce image sharpness or create a fine grainy appearance, especially on white backgrounds and small text.
The AG level should therefore be selected according to:
For projects requiring customized shape, thickness, printing or AG processing, the surface treatment can be integrated into the touchscreen cover glass design.
AG is commonly suitable for:
AR stands for anti-reflection.
Unlike AG, which scatters reflected light, an AR coating is designed to reduce the amount of light reflected from the glass surface. This helps the touchscreen maintain a clearer and more transparent appearance.
AR treatment is especially useful when image detail is important. Medical instruments, laboratory equipment and measurement systems may display small text, waveforms, charts or detailed operating data. In these applications, the screen should reduce reflection without creating too much surface haze.
An anti-reflection glass surface may also provide a cleaner and more premium visual effect than heavily textured AG glass.
The main consideration is that AR coating normally requires more complex processing. Depending on the coating design and viewing angle, a slight blue, green or purple reflection may sometimes be visible.
AR is commonly suitable for:
For projects where readability, wide viewing angles and frequent cleaning are important, AR can be evaluated together with MAXEN’s medical LCD display solutions.
AF stands for anti-fingerprint. It may also be described as anti-smudge, oleophobic or easy-clean coating.
An AF coating reduces the adhesion of fingerprints, skin oil and water marks. It does not make fingerprints disappear completely, but it makes them less visible and easier to wipe away.
AF treatment can also reduce surface friction, helping a finger move more smoothly across the touchscreen during repeated operation.
This makes an AF coating a practical option for equipment that is touched frequently throughout the day.
Imagine a self-service kiosk in a public area. Even if the screen is bright and responsive, visible fingerprints can quickly make it look dirty. Adding AF treatment helps maintain a cleaner interface and reduces daily cleaning effort.
AF is commonly suitable for:
AF performance may gradually decrease after long-term abrasion or repeated cleaning. The cleaning method and chemicals used on the finished equipment should therefore be considered during development.
Below are recommendations for AG / AR / AF combinations in common B2B scenarios to help you screen options at design stage.
Typical scenarios
EV charging stations, outdoor energy management terminals, outdoor information terminals, agricultural / construction machinery controllers, etc.
Main pain points
Recommended combination
Typical scenarios
Production line HMIs, PLC operator panels, CNC / machine control terminals, etc.
Main pain points
Recommended combination
Typical scenarios
Patient monitors, analyzers, diagnostic and lab instruments, etc.
Main pain points
Recommended combination
Typical scenarios
Access control panels, video door phones, time-attendance devices, and face/fingerprint recognition terminals.
Main pain points
Recommended combination
To let your touchscreen supplier propose a suitable AG / AR / AF faster, it is helpful to provide at least the following information:
The more clearly this information is defined in the requirement document or RFQ, the easier it is for the supplier to converge on an appropriate surface treatment solution and avoid multiple iterations.
In real projects, AG / AR / AF are applied on the cover glass of the projected capacitive touchscreen, working together with the internal TFT LCD module to improve both visual performance and touch experience.
MAXEN can provide, based on project needs:
If you are planning a new HMI, EV charger, access control panel or video doorbell and need to evaluate AG / AR / AF options, you can send us your basic requirements (size, brightness, interface, environment and target quantity) via sales@maxen-lcddisplay.com. Sharing these key parameters upfront helps us quickly propose suitable surface treatment options and reduce communication and sampling lead time.
melody.xia@maxen-lcddisplay.com
