Acid Etched Glass vs. Scratch Graffiti: What Austin Property Managers Need to Know

Both types of graffiti can look identical until you know what to look for.

The Call I Get Wrong Most Often Starts Like This

Someone calls and says they've got graffiti on their commercial windows. Tags, markings, letters — glass looks frosted or hazed where the damage is. They want to know if it can be fixed.

My first question is always: Was something drawn on the glass, or was something applied to it?

That question sounds simple. The answer to it determines everything — the repair approach, the tools, the time, the risk profile, and whether the glass can be saved at all. Because there are two very different types of graffiti damage on glass, and they look nearly identical until you know what to look for:

• Scratch graffiti — a sharp object (key, nail, glass cutter, metal tool) dragged across the surface, physically displacing glass material
• Acid etch graffiti — a chemical agent (typically hydrofluoric acid or an acid-based compound) applied to the surface, chemically dissolving the glass structure itself

If you're managing commercial property in Austin and you're staring at glass graffiti right now, this post is the fastest way to understand what you're dealing with — before you call anyone.

The polishing process differs significantly depending on whether the damage is mechanical or chemical.

What's Actually Happening to the Glass — and How to Tell

Scratch graffiti: physical damage

When someone drags a key or sharp object across glass, they displace material. The scratch is a physical groove — a channel in the glass surface where material has been removed or pushed aside. Under the right lighting, scratch graffiti often has directionality: you can see the path of the tool, sometimes with edge ridges on either side of the mark.

The repair for scratch graffiti is mechanical: we use a sequence of progressively finer abrasive discs to level the surrounding glass down to the depth of the scratch, then polish back to optical clarity. The grit selection and sequence depends on how deep the scratch is — which is why we always assess first.

Acid etch graffiti: chemical damage

When someone applies an acid compound to glass, the chemical reacts with the silica in the glass surface and dissolves it. Acid etch damage looks frosted or milky — sometimes with soft, diffuse edges rather than sharp lines, depending on how the agent was applied and whether it ran or pooled.

The key visual difference: acid etch graffiti often has a more uniform haziness within the damaged area, while scratch graffiti tends to have harder lines and visible directionality. Touch is another indicator — scratch graffiti has physical texture you can feel with a fingernail; acid etch damage is often smooth to the touch because the surface has been chemically dissolved, not cut.

The repair for acid etch is also abrasive — but the starting approach, the chemistry of any compounds used, and the risk of enlarging the damage area differ from scratch repair. It requires a specialist who has actually worked on acid etch damage before, not just someone who does scratch removal.

The cerium oxide polish stage — where optical clarity is fully restored.

What Proper Diagnosis Actually Looks Like

A qualified glass resurfacing specialist will not quote you a repair without inspecting the glass in person — or at minimum from high-quality close-up photos. Here's what a proper pre-repair assessment covers:

• Visual inspection under raking light. Directionality, edge sharpness, pooling patterns — lighting reveals what flat photos miss.
• Tactile assessment. Running a fingernail or pick across the damaged area confirms whether there's physical texture (scratch) or smooth dissolution (acid etch).
• Glass type identification. Tempered, laminated, coated, or filmed glass all carry different repair risk profiles regardless of the damage type. A specialist needs to know what they're working on.
• Damage boundary mapping. Understanding where the damage ends matters — especially with acid etch, where the affected area can be larger than it initially appears.
• Demo patch. On any job where there's uncertainty, we do a small test repair on an inconspicuous area first to confirm the glass responds as expected before committing to the full scope.

The repair itself — whether for acid etch or scratch — follows a grit progression sequence ending with a cerium oxide polish that restores optical clarity. The full process and the reasoning behind each stage are covered in our glass resurfacing guide.

When both types are caught early and diagnosed correctly, the glass is nearly always restorable. The problem is when someone starts the wrong repair on the wrong damage type — or when an untrained technician treats acid etch like scratch graffiti and causes irreversible enlargement of the damaged area.