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1. Foreign bodies with a diameter up to 1mm, without any cracks or scratches around them 1 per 1 dm² area acceptable *
2. Foreign bodies with a diameter above 1 mm unacceptable
3. Air bubbles with a diameter up to 0,5 mm acceptable when sparsely scattered
4. Air bubbles up till 1 mm single ones acceptable – not in clusters
5. Air bubbles up to 2 mm 3 per 1 dm² area acceptable
6. Bursting air bubbles unacceptable
7. Longitudinal air bubbles up to 5 mm 1 item acceptable *
8. Oval shape, lack of symmetry, convexity or concavity acceptable within the bounds of tolerance and when no deformation of the product present
9. Creased surfaces, overlapping glass layers unacceptable
10. Waviness of the surface acceptable when hardly noticeable
11. Scratches and scores acceptable when hardly noticeable*
12. Chips on the edges 3 acceptable, depth up to 1,5 mm (applied to shades under fitting, where chips are hidden)
13. Smudges, trails acceptable when unnoticeable from a distance up to 1 meter
14. Thickness of the walls 2 – 4 mm

However, not when they affect the effect of the illumination The agreement on standard quality requirements different than those presented above is possible on a separate arrangement with the Client, if approved by the Department of Quality Control, as well as the President of the Board.