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DOI is one of the three concepts designating the reflected image quality, therefore, low DOI is an important defect for automotive OEM and car repair coatings. Low DOI is revealed by observation of scattering on the vicinity of the main light beam reflected with an angle of 20° from the varnish surface. However, scaterring in low DOI occurs in a much narrower angle interval than that of haze defect. Low DOI is perceived as reduction in sharpness and distinctness on the edges of the reflected image. Measurement of DOI is performed by DOI-meters produced by equipment producers. Low DOI can arise from light scattering caused by crystalline additives or binders in the coating film, or by tiny wrinkles on the surface of the coating.