Standard · Systems, environments and degradation
ISO 2813
Measuring the specular gloss of paint films.
A glossmeter shines light at a set angle and measures how much is reflected. ISO 2813 uses three geometries:
- 60°: the general geometry, for medium gloss.
- 20°: spreads out the readings of high-gloss films.
- 85°: resolves low-gloss and matt finishes.
Choosing the angle
Start with a reading at 60°. Above 70 gloss units at 60°, measure again at 20°. Below 10 gloss units, measure at 85°. To compare a high-gloss coating before and after weathering, stay at 60°: there it gives better precision than 20°.
A gloss result is meaningless without its angle: report both, for example "82 GU at 60°". ASTM D523 uses the same three geometries.
1 practice item in the members area mentions ISO 2813 (CIP 2: 1).
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This page describes the subject of ISO 2813 in our own words; it does not reproduce the standard. For the full text, buy the current edition from ISO. Checked on 2026-10-14; errors go in the corrections log. CoatMentor is an independent study aid. It is not affiliated with ISO, AMPP, SSPC, NACE International, ASTM or FROSIO.