ISO 6504-3:2019 PDF

Overview

ISO 6504-3:2019 - Paints and varnishes: Determination of hiding power - Part 3 covers standardized laboratory methods to measure the hiding power (opacity) of white or light-coloured paints intended for masonry, concrete and interior use. The third edition (2019) defines procedures for measuring tristimulus values (Y and Y10 > 25) over black and white substrates or using a colourless transparent foil placed over black and white panels, and for calculating hiding power and spreading rate for interior coatings.

Key topics and technical requirements

• Scope and materials: Applies to white or light-coloured paints for masonry, concrete and interior walls/ceilings; requires Y and Y10 > 25 for test specimens.
• Measurement principle: Determination of tristimulus values (Y and Y10) over black and white panels and calculation of hiding power from these values. Spectrophotometric colour measurement is used for tristimulus values.
• Substrate and methods: Three methods are specified:
  • Method A: Coating on a transparent foil measured over black/white panels.
  • Method B: Direct application to black and white charts.
  • Method C: New (2019) method suitable for waterborne coatings; uses two coating thicknesses and interpolation/graphical determination.
• Spreading rate: Procedures for calculating theoretical and practical spreading rates are included. The standard allows use of ISO 3233-3 calculation or a simplified method referenced in EN 13300 for low-evaporation interior coatings.
• Supporting measurements: Density (ISO 2811), non-volatile matter content (ISO 3251) and sample preparation (ISO 1513 / ISO 15528) are referenced for auxiliary determinations.
• Data handling: Includes calculation procedures, graphical interpolation between thicknesses, precision considerations and test-report requirements. Annex A provides interlaboratory comparison information.

Practical applications and users

• Paint and coatings manufacturers: product development, formulation optimization and quality control of opacity/coverage.
• Independent test laboratories and QC departments: standardized method for reproducible hiding-power measurements and reporting.
• Specifiers, architects and contractors: verify product performance claims for interior masonry and concrete coatings.
• Regulatory bodies and procurement: ensure compliance with performance standards and product classification (EN 13300).

Related standards

• ISO 6504 series (other parts on hiding power)
• ISO 3251 (non-volatile-matter content)
• ISO 2811 (density)
• ISO 3233-3 (volume of non-volatile matter calculation)
• EN 13300 (classification of water‑borne interior coatings)
• ISO 1513, ISO 15528, ISO 11664-2

Keywords: ISO 6504-3:2019, hiding power, opacity, paints for masonry, concrete, interior use, tristimulus Y, spreading rate, EN 13300, Method C, spectrophotometer.