Overview
EN ISO 28199-2:2021 - Paints and varnishes: Evaluation of properties of coating systems related to the spray application process (Part 2) - defines test methods for assessing how coating materials behave when applied by spray. The standard covers colour stability, process hiding power, re‑dissolving, overspray absorption, wetting, surface texture and mottling of coatings applied to test panels under defined spray conditions. It is part of the ISO 28199 series and is intended for use in research, development, production and quality control of spray-applied coating systems.
Key topics and technical requirements
- Colour stability / colour evaluation - methods for evaluating colour changes and colour matching after spray application and film formation.
- Process hiding power - assessment of a coating’s ability to hide substrate features when applied in a spray process at specified film thicknesses.
- Re‑dissolving - procedures to check susceptibility of applied films to re‑dissolving under defined conditions (important for solvent interactions and process compatibility).
- Overspray absorption - methods to assess how adjacent surfaces or masking materials absorb overspray during spraying operations.
- Wetting - evaluation of wetting behaviour of coating materials on substrates when delivered by spray equipment.
- Surface texture and mottling - measurement and visual assessment of surface texture (including introduced long‑ and short‑wavelength limits) and mottling; the 2021 edition separates measurement techniques and visual evaluation for mottling.
- Measurement and visual methods - combines instrumental measurements (linked to ISO references) with visual assessment; film thickness and colour/gloss metrics are used to contextualize results.
Note: EN ISO 28199-2:2021 references related test standards for film thickness, colour and gloss and updates normative references from the previous edition.
Applications
- Product development and formulation optimization for automotive, industrial and plastic coatings tailored to spray processes.
- Quality control (QC) and production acceptance testing to ensure consistent colour stability, hiding performance and surface quality.
- Process validation and troubleshooting (e.g., overspray issues, poor wetting or mottling on critical parts).
- Comparative testing for supplier qualification and specification compliance.
Who should use this standard
- Coating and paint manufacturers, formulators and R&D teams
- Automotive OEMs and tier‑1 suppliers involved in spray coating lines
- Independent test laboratories and QC/QA departments
- Process engineers and coating applicators focused on spray application optimization
Related standards
EN ISO 28199-2:2021 is essential for anyone evaluating spray-applied coatings where appearance, hiding, surface texture and process robustness are critical. Keywords: EN ISO 28199-2:2021, colour stability, process hiding power, overspray absorption, wetting, surface texture, mottling, spray application, paints and varnishes testing.
