ASTM D5531-17(2023)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D5531 − 17 (Reapproved 2023)
Standard Guide for
Preparation, Maintenance, and Distribution of Physical
Product Standards for Color and Geometric Appearance of
Coatings
This standard is issued under the fixed designation D5531; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D2244 Practice for Calculation of Color Tolerances and
Color Differences from Instrumentally Measured Color
1.1 This guide covers three levels of physical product
Coordinates
standards for color or appearance, or both, commonly used in
D3134 Practice for Establishing Color and Gloss Tolerances
the coatings industry, provides terminology to describe each
D4086 Practice for Visual Evaluation of Metamerism
level, and describes techniques for generating and caring for
D4449 Test Method for Visual Evaluation of Gloss Differ-
standards.
ences Between Surfaces of Similar Appearance
1.2 The values stated in SI units are to be regarded as the
E284 Terminology of Appearance
standard. The values given in parentheses are for information
E308 Practice for Computing the Colors of Objects by Using
only.
the CIE System
1.3 This standard does not purport to address all of the
E430 Test Methods for Measurement of Gloss of High-Gloss
safety concerns, if any, associated with its use. It is the Surfaces by Abridged Goniophotometry
responsibility of the user of this standard to establish appro-
E805 Practice for Identification of Instrumental Methods of
priate safety, health, and environmental practices and deter- Color or Color-Difference Measurement of Materials
mine the applicability of regulatory limitations prior to use.
E1164 Practice for Obtaining Spectrometric Data for Object-
1.4 This international standard was developed in accor- Color Evaluation
dance with internationally recognized principles on standard-
E1331 Test Method for Reflectance Factor and Color by
ization established in the Decision on Principles for the Spectrophotometry Using Hemispherical Geometry
Development of International Standards, Guides and Recom-
E1345 Practice for Reducing the Effect of Variability of
mendations issued by the World Trade Organization Technical
Color Measurement by Use of Multiple Measurements
Barriers to Trade (TBT) Committee. E1347 Test Method for Color and Color-Difference Mea-
surement by Tristimulus Colorimetry
2. Referenced Documents E1349 Test Method for Reflectance Factor and Color by
Spectrophotometry Using Bidirectional (45°:0° or 0°:45°)
2.1 ASTM Standards:
Geometry
D16 Terminology for Paint, Related Coatings, Materials, and
Applications 2.2 Society of Automotive Engineers Standard:
D523 Test Method for Specular Gloss SAE J1545 Recommended Practice for Instrumental Color
D823 Practices for Producing Films of Uniform Thickness Difference Measurement for Exterior Finishes, Textiles,
of Paint, Coatings and Related Products on Test Panels and Colored Trim
D1729 Practice for Visual Appraisal of Colors and Color
Differences of Diffusely-Illuminated Opaque Materials 3. Terminology
3.1 The definitions in Terminology E284 and D16 are
applicable to this standard. The terms in E284 take precedence
This guide is under the jurisdiction of ASTM Committee D01 on Paint and
over those in D16 if differences exist.
Related Coatings, Materials, and Applications and is the direct responsibility of
3.2 Definitions of Terms Specific to This Standard:
Subcommittee D01.26 on Optical Properties.
Current edition approved July 1, 2023. Published August 2023. Originally
approved in 1994. Last previous edition approved in 2017 as D5531 – 17. DOI:
10.1520/D5531-17R23.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from American Architectural Manufacturers Association (AAMA),
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM 1827 Walden Office Square, Suite 550, Schaumburg, IL 60173-4268, http://
Standards volume information, refer to the standard’s Document Summary page on www.aamanet.org.Available from Society of Automotive Engineers (SAE), 400
the ASTM website. Commonwealth Dr., Warrendale, PA 15096-0001, http://www.sae.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5531 − 17 (2023)
3.2.1 concept color, n—the color of the material submitted 6.2 The coatings supplier should produce the physical
by the customer as the target for generating the master product standards for color. They must have the same spectral
standard. character at all viewing and illuminating geometries of concern
as the coating.
3.2.2 master standard, n—the physical standard for color
that the customer approves as the target for visual,
6.3 The standard should have the same geometric appear-
spectrophotometric, and colorimetric evaluation of all products
ance (nonspectral) characteristics as the final product. Changes
referenced to that standard.
in geometric characteristics may influence the noncolor aspects
3.2.2.1 Discussion—In SAE J1545 this is referred to as the
of appearance such as gloss and texture. They may also affect
“official” standard.
the assessed color of the coating with respect to both instru-
mental measurement and visual perception.
3.2.3 duplicate master standard, n—a replicate of the master
standard that serves as the master standard at a secondary
6.4 The desire for permanent physical product standards for
location.
color will sometimes lead people to consider other material
3.2.3.1 Discussion—In SAE J1545 this is referred to as the
such as ceramic for standards, but such substitution should be
“reference” standard.
avoided. Fairman states: “While a ceramic tile may be
recognized as a material of greater permanence than the
3.2.4 working standard, n—the physical product standard
organic material being standardized, the probability of the
for color or appearance, or both, used for routine measurements
introduction of metamerism between the two dissimilar mate-
and visual assessments in the laboratory and at the production
rials far outweighs any possible permanence gains.”
site.
7. Three Levels of Physical Product Standards for Color
4. Summary of Guide
and Appearance
4.1 Product standards are the only standards by which
7.1 The concept color submitted by the customer should not
products should be accepted or rejected for color or appear-
become the master standard because it may be made of
ance. For each colored product, a hierarchy of product stan-
different material or have gloss or texture (geometric appear-
dards should be developed. These include: a master standards,
ance) different from the final product. The concept color simply
duplicate master standards, and working standards. A master
represents the customer’s best effort to illustrate the desired
standard is generated from the concept color submitted by the
color for the coating. The concept color is to be “matched” by
customer. Duplicate master standards, when needed, are gen-
the master standard, usually per acceptance by the customer.
erated from the master standard. Working standards are gener-
The master standard represents the target, both spectrally and
ated from a duplicate master standard. They are used in the
geometrically, for the manufactured coating. It becomes the
laboratory or on the production line to accept or reject the color
reference by which the coating is accepted or rejected. Once
or appearance of coatings. After initial generation, product
the master standard is approved by the customer, the concept
standards must be maintained to ensure they remain valid. This
color should be properly stored for possible future use.
guide considers the characteristics of product standards, factors
to be considered in their creation, and factors to be considered 7.2 The master standard is the reference for judging the
in their replacement. color of duplicate master standards. Although in the case of a
dispute it is the ultimate reference for color and geometric
5. Significance and Use appearance. It should not be used for routine evaluations in the
laboratory or at the production site.
5.1 High quality physical product standards for color or
appearance are the keystone of a successful color control
7.3 Multiple duplicate master standards should be prepared
program. Standards are often grouped into three major catego- at the same time. Duplicate master standards are intended to be
ries: product standards, intermediate production control
identical to the master standard. Because there will be variation
standards, and instrument standards. This guide deals only with in perceived or measured characteristics of duplicate master
physical product standards. Some instrument-based color con-
standards, buyer and seller must agree on tolerances for
trol programs use “numerical standards,” derived from instru- “duplicate master standards.” As examples, Fairman suggests
mental measurements of a physical product standard. th
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