Shower Glass2 min read

Glass Inspection from Both Faces: A Four-View Defect Location Method

Locate marks on glass by inspecting both faces in transmission and reflection before attributing a defect to the nano coating.

Updated · NANOLAB Knowledge

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

A mark visible through glass may sit on the treated face, the opposite face or within the glazing construction. Treating the wrong face wastes time and can introduce damage. A four-view inspection helps locate the problem before any corrective chemistry is chosen.

Establish orientation

Identify face A and face B using the job record and a suitable external marker. For installed glass, note which face is accessible and which is believed to be treated. Do not infer the coated side solely from a casual water test, especially when cleaning residues or prior treatments are present.

View Inspection purpose
Through A toward a target Locate the visible mark in the overall pane
Reflection from A Look for surface residue on A
Through B, where accessible Check the same location from the reverse side
Reflection from B Look for surface residue on B

Keep the target location fixed

Use a photograph and a diagram referenced to an edge or fitting. Avoid writing directly on the evaluated surface. Change viewing position and focus deliberately, and compare the mark with a nearby clear area.

A practical diagnostic example

A shower door looks cloudy from the room side after coating. Inspection from the reverse side reveals a cleaning streak on the untreated face. Appropriate cleaning of that face resolves the visible problem. Reworking the coating would have addressed the wrong layer.

Another pane may show a persistent feature that cannot be located confidently on either accessible face. That is a reason to involve the glazing supplier, not proof that the defect lies inside the glass. Optical appearance alone may not establish the construction or cause.

Confirm before correcting

Use a small, suitable cleaning check only after confirming material and product compatibility. Record the result when dry. If the mark remains, retain the four-view record for technical support rather than escalating through increasingly aggressive cleaners.

This method is a location aid. It does not replace specialist assessment of scratches, etched surfaces, laminated glass defects or factory coatings.

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