GGF Guidelines
Glass Scratches & Visual Imperfections
The Glass and Glazing Federation (GGF) sets out industry standards for acceptable visual quality in flat transparent glass (including float, laminated, toughened, and coated glass). Below is a summary of the inspection criteria and acceptable tolerances:
Inspection Conditions
- Glass should be inspected in natural daylight, not direct sunlight.
- Glass must be clean and dry.
- View from a minimum distance of 3 meters for toughened/laminated/coated glass.
- Inspect from three angles: straight on, and 45° from both the left and right.
- A 50mm wide band around the edge is excluded from inspection.
Acceptable Imperfections
- Fine scratches up to 25mm long (provided they are not grouped or visually obtrusive).
- Minute embedded particles.
- Small air bubbles or blisters.
Unacceptable Defects
- Bunched or noticeable imperfections that distract visually.
- Smears, fingerprints, or dirt on either glass face.
- Contaminants or marks inside sealed units.
Special Considerations
- Toughened Glass: May show natural phenomena like haze, bowing, or anisotropy. These are not considered defects.
- Laminated Glass: Due to its layered structure, more imperfections may be visible. A 25% greater tolerance is allowed compared to standard float glass.
Inspection Conditions
- Glass should be inspected in natural daylight, not direct sunlight.
- Glass must be clean and dry.
- View from a minimum distance of 3 meters for toughened/laminated/coated glass.
- Inspect from three angles: straight on, and 45° from both the left and right.
- A 50mm wide band around the edge is excluded from inspection.
Acceptable Imperfections
- Fine scratches up to 25mm long (provided they are not grouped or visually obtrusive).
- Minute embedded particles.
- Small air bubbles or blisters.
Unacceptable Defects
- Bunched or noticeable imperfections that distract visually.
- Smears, fingerprints, or dirt on either glass face.
- Contaminants or marks inside sealed units.
Special Considerations
- Toughened Glass: May show natural phenomena like haze, bowing, or anisotropy. These are not considered defects.
- Laminated Glass: Due to its layered structure, more imperfections may be visible. A 25% greater tolerance is allowed compared to standard float glass.
