ISO 4628-6-2023 PDF

Full title and description

Paints and varnishes — Evaluation of quantity and size of defects, and of intensity of uniform changes in appearance — Part 6: Assessment of degree of chalking by tape method. This international standard provides pictorial reference charts and a tape‑paper assessment technique for rating the degree of chalking on coating surfaces.

Abstract

This document gives pictorial reference standards for designating the degree of chalking of paint coatings and describes a reproducible tape‑method to determine a chalking grade. It highlights the need to distinguish true chalking (degradation products) from surface contamination or adhering dirt, and it provides guidance for comparative visual rating against the graphic standard.

General information

• Status: Published
• Publication date: October 2023
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 87.040 (Paints and varnishes)
• Edition / version: Edition 4 (2023)
• Number of pages: 5

Scope

ISO 4628-6:2023 provides pictorial reference standards and a tape‑paper procedure to assess the degree of chalking (formation of a fine powdery residue) on coating surfaces. The method is intended for use on a variety of coating surfaces (smooth and rough) and is intended as a comparative visual technique; care must be taken to avoid confusing chalking with adhering dirt or other surface deposits.

Key topics and requirements

• Pictorial reference chart(s) for designation of chalking grades (graphic standards for comparison).
• Detailed tape‑paper (adhesive tape) sampling procedure to remove and collect chalking for visual comparison and grading.
• Instructions for preparing and comparing samples against the reference images to assign a chalking grade.
• Guidance to distinguish true degradation (chalk) from dirt or contamination and limitations of the method (e.g., heavily soiled surfaces).
• Recommendation to use controlled visual assessment lighting and procedures as referenced (see ISO 13076) when performing comparisons.

Typical use and users

This standard is used by paint and coating manufacturers, independent testing laboratories, quality control and inspection personnel, corrosion and coatings engineers, product developers and specification writers who need a reproducible, visual/comparative method to quantify the degree of chalking on coatings after exposure or in service.

Related standards

ISO 4628-6 is part of the ISO 4628 series (evaluation of degradation of coatings). See ISO 4628-1 for the general introduction and designation system used across the series; related parts cover blistering, rusting, cracking, flaking, delamination and other specific defect assessments. Visual assessment lighting and procedures referenced in this part are covered by ISO 13076.

Keywords

chalking, tape method, paints and varnishes, visual assessment, pictorial reference, coating degradation, quality control, ISO 4628

FAQ

Q: What is this standard?

A: An ISO international standard (ISO 4628-6:2023) that defines pictorial reference grades and a tape‑paper assessment procedure for measuring the degree of chalking on paint and varnish coatings.

Q: What does it cover?

A: It covers a visual/comparative method (including pictorial charts) and a tape sampling technique for designating and rating the degree of chalking; it gives guidance on distinguishing true chalk from surface dirt and on conditions for reliable comparison.

Q: Who typically uses it?

A: Coating manufacturers, independent test laboratories, QC/inspection teams, coatings engineers and specification authors who require consistent, reproducible assessment of chalking on coated surfaces.

Q: Is it current or superseded?

A: Current — ISO 4628-6 was published in 2023 (Edition 4) and replaces the earlier 2011 edition; it is the active edition as published by ISO in October 2023.

Q: Is it part of a series?

A: Yes — it is Part 6 of the ISO 4628 series (the series provides standardized pictorial or procedural methods for evaluating different types of coating defects and uniform appearance changes; ISO 4628-1 gives the general system and designation conventions).

Q: What are the key keywords?

A: Chalking, tape method, pictorial reference, coating degradation, visual assessment, paints and varnishes, ISO 4628.