Overview - ISO 2813:2014 (Paints and varnishes: gloss at 20°, 60°, 85°)
ISO 2813:2014 specifies a standardized method for determining the gloss of coatings using three measurement geometries: 20°, 60° and 85°. The procedure applies to non-textured coatings on flat, opaque substrates and produces a numerical gloss value expressed in gloss units (GU). The standard defines instrument geometry, calibration, measurement procedure and reporting requirements to ensure comparable results between laboratories and production sites.
Key topics and technical requirements
- Measurement geometries: Required incident angles are (20.0 ± 0.1)°, (60.0 ± 0.1)° and (85.0 ± 0.1)°.
- 20°: recommended for high-gloss surfaces
- 60°: general-purpose / semi-gloss range
- 85°: for matt/low-gloss surfaces
- Reference scale: Polished black glass with refractive index 1.567 (at specified wavelength) is assigned a value of 100 GU for all three geometries; results are expressed as integers (rounded to the nearest GU).
- Glossmeter design and apertures: The standard specifies source/receptor aperture angles (parallel and perpendicular to plane of reflection) to limit received scattered light and ensure consistent field-of-view (see Table 1 in the standard).
- Spectral adaptation and filtering: Receptor filtering and spectral response must be controlled so measurements correspond to a standard illuminant (C) and CIE photopic response (observer adaptation is required).
- Calibration and adjustment: Instruments must be calibratable against certified reference materials and working standards; Annex B covers calibration standards.
- Precision and quality control: Annex D presents interlaboratory precision data (repeatability and reproducibility) and Annex A lists possible sources of error; the standard also specifies required test reporting elements.
Practical applications and users
ISO 2813 is used for objective measurement of surface appearance where gloss/reflectivity matters. Typical uses and users include:
- Quality control in paint, varnish and coatings manufacturing
- R&D and formulation labs comparing gloss performance
- Coatings specification and acceptance testing in automotive, furniture, architectural, industrial and consumer-product sectors
- Third‑party test laboratories and certification bodies
- Procurement and standards writers defining appearance requirements
Benefits: consistent, repeatable gloss values for production acceptance, appearance matching, and product development decisions.
Related standards
- ISO 1514 - Standard panels for testing
- ISO 2808 - Determination of film thickness
- ISO 4618 - Terms and definitions for paints and varnishes
Keywords: ISO 2813:2014, gloss measurement, glossmeter, gloss units GU, paints and varnishes, 20° 60° 85°, calibration, specular reflection, coating quality control.
