Shower Glass2 min read

Transparent Coatings on Glass: Separate Transmission from Reflection

Evaluate a clear coating on glass using transmitted and reflected views, because a shiny reflection does not prove optical clarity.

Updated · NANOLAB Knowledge

Illustration of a frameless shower screen with water droplets, a squeegee and folded microfiber
Editorial illustration

Glass can reflect a sharp light source while still looking cloudy when viewed through. A transparent coating assessment therefore needs more than a glossy photograph. Separate the view through the glass from the appearance of reflected light.

Choose the optical question

Transmission concerns light passing through the sample. Reflection concerns light returned toward the observer. Haze and image clarity describe additional aspects of appearance; they should not be replaced by a single generic “clarity” score without explaining the method.

View Practical observation
Through glass toward a fixed target Visibility, cloudiness and distortion
Reflected light on the treated face Streaks and local unevenness
Oblique view across the surface Application boundaries and residue

Build a fair comparison

Use representative glass with the same thickness and existing surface treatments. Clean both faces appropriately and record which face receives the coating. Keep background, target distance, light position and viewing geometry consistent. A darker background can make a defect more visible without the glass itself changing.

Inspect after the relevant cure stage

Record the interval after application and follow the product’s inspection guidance. Do not compare a freshly levelled sample with one that has completed its specified cure and assume the difference is permanent.

In an illustrative review, both samples show bright reflections, but one blurs a printed target viewed through the glass. That observation warrants a transmission-focused assessment. It cannot be resolved by showing a second photograph with a brighter reflected lamp.

Use instruments for claims that require them

A visual screening board is useful for selecting samples and locating defects. Quantitative transmission or haze claims require a suitable instrument, method and sample geometry. Record the actual metric instead of converting a visual rating into a laboratory percentage.

Keep optical acceptance separate from water repellency. A sample that beads strongly can still be unsuitable if its appearance is unacceptable. For shower glazing, the practical goal is an appropriate combination of clear appearance and maintainability on the specified glass.

Technical references

The sources below support the stated concepts or describe their own methods. The worked scenarios are editorial examples, not NANOLAB test results.

Discuss a shower-glass coating project. For application and care, use the current instructions for the exact product.