Question: How to recognize the etched side?

Answer:

Recognizing the etched (AG/anti-glare) side of optical glass is crucial for quality control and application matching. Here are 3 practical and high-precision methods:

 

1. Visual Light Reflection Test (Most Used)

Place the glass under natural light or fluorescent lamps. Observe the light reflection on both sides: the etched side will produce diffuse reflection, with blurred and scattered light (matte, non-glare effect); the non-etched side will form a clear, mirror-like specular reflection of the light source. This method is the most convenient and widely used in on-site inspection, with 100% accuracy for standard AG glass.

2. Tactile Touch Test

Gently slide your finger across the glass surface. The etched side has a matte, slightly rough texture (smooth and non-sticky hand feeling), while the non-etched side is smooth and flat. Note: This method is not suitable for AF-coated glass, as the AF layer will change the surface touch feeling.

3. Backlighting Transparency Test

Hold the glass up to a strong light source and observe from the opposite side. The etched side shows a frosted, semi-opaque matte effect, while the non-etched side is fully transparent. This method is especially effective for high-haze AG glass, making it easy to distinguish even for thick glass.

 

In summary, the visual light reflection test is the first choice for quick identification, and it can be combined with the tactile test for double verification. Our AG optical glass undergoes strict process control, ensuring clear distinction between etched and non-etched sides and stable product performance.