ASTM D4303-10(2022)

Standard Test Methods for Lightfastness of Colorants Used in Artists' Materials

SIGNIFICANCE AND USE
5.1 The retention of chromatic properties by a colorant over a long period of years is essential in a work of art. Accelerated exposure simulates color changes that may reasonably be expected. The producer and the user of artists' materials, therefore, can be apprised of suitable colorants.  
5.2 Variations in results may be expected between the test methods. Also, some variation may be expected when the same test is repeated. Variations in Methods A and B are due to differences in outdoor conditions that are not accounted for in testing to equivalent radiant exposures. Information on sources of variability and strategies for addressing variability in laboratory accelerated exposure tests is found in Guide G141.  
5.3 This standard does not cover factors other than lightfastness that can affect the permanence of art materials.
SCOPE
1.1 Four test methods to accelerate the effects of long term indoor illumination on artists’ materials are described below. One of the natural daylight methods and one of the xenon-arc methods are used to categorize the lightfastness of colorants.  
1.1.1 Test Method A—Exposure in southern Florida to natural daylight filtered through window glass.  
1.1.2 Test Method B—Exposure in Arizona to natural daylight filtered through window glass.  
1.1.3 Test Method C—Exposure in a non-humidity controlled xenon-arc device simulating daylight filtered through window glass.  
1.1.4 Test Method D—Exposure in a humidity controlled xenon-arc device simulating daylight filtered through window glass.  
1.2 These test methods are used to approximate the color change that can be expected over time in colorants used in artists' materials exposed indoors to daylight through window glass.  
Note 1: The color changes that result from accelerated exposure may not duplicate the results of normal indoor exposure in a home, art gallery, or museum. The relative resistance to change, however, can be established so colored materials can be assigned to categories of relative lightfastness.
Note 2: Users who wish to test colored materials under fluorescent illumination should consult Practice D4674.  
1.3 Lightfastness categories are established to which colorants are assigned based on the color difference between specimens before and after exposure.  
1.4 Color difference units are calculated by the CIE 1976 L*a*b* color difference equation.  
1.5 These test methods apply to colored artists’ materials.  
1.6 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.8 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.

General Information

• Status: Published
• Publication Date: 30-Nov-2022
• ICS: 87.060.10 - Pigments and extenders
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.57 - Artist Paints and Related Materials

Relations

• Refers: ASTM E1347-06(2020) - Standard Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry
• Effective Date: 01-May-2020

Standards Content (Sample)

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: D4303 − 10 (Reapproved 2022)
Standard Test Methods for
1
Lightfastness of Colorants Used in Artists’ Materials
This standard is issued under the fixed designation D4303; 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 responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.1 Four test methods to accelerate the effects of long term
mine the applicability of regulatory limitations prior to use.
indoor illumination on artists’ materials are described below.
1.8 This international standard was developed in accor-
One of the natural daylight methods and one of the xenon-arc
dance with internationally recognized principles on standard-
methods are used to categorize the lightfastness of colorants.
ization established in the Decision on Principles for the
1.1.1 Test Method A—Exposure in southern Florida to
Development of International Standards, Guides and Recom-
natural daylight filtered through window glass.
mendations issued by the World Trade Organization Technical
1.1.2 Test Method B—Exposure in Arizona to natural day-
Barriers to Trade (TBT) Committee.
light filtered through window glass.
1.1.3 Test Method C—Exposure in a non-humidity con-
2. Referenced Documents
trolled xenon-arc device simulating daylight filtered through
2
2.1 ASTM Standards:
window glass.
D2244 Practice for Calculation of Color Tolerances and
1.1.4 Test Method D—Exposure in a humidity controlled
Color Differences from Instrumentally Measured Color
xenon-arc device simulating daylight filtered through window
Coordinates
glass.
D4302 Specification for Artists’ Oil, Resin-Oil, and Alkyd
1.2 These test methods are used to approximate the color
Paints
change that can be expected over time in colorants used in
D4674 PracticeforAcceleratedTestingforColorStabilityof
artists’ materials exposed indoors to daylight through window
Plastics Exposed to Indoor Office Environments
glass.
D5067 Specification for Artists’ Watercolor Paints
NOTE 1—The color changes that result from accelerated exposure may
D5098 Specification for Artists’Acrylic Dispersion Paints
not duplicate the results of normal indoor exposure in a home, art gallery,
D5724 Specification for Gouache Paints
or museum.The relative resistance to change, however, can be established
D6901 Specification for Artists’ Colored Pencils
so colored materials can be assigned to categories of relative lightfastness.
E284 Terminology of Appearance
NOTE 2—Users who wish to test colored materials under fluorescent
illumination should consult Practice D4674. E1347 Test Method for Color and Color-Difference Mea-
surement by Tristimulus Colorimetry
1.3 Lightfastness categories are established to which colo-
E1348 Test Method for Transmittance and Color by Spec-
rants are assigned based on the color difference between
trophotometry Using Hemispherical Geometry
specimens before and after exposure.
E1349 Test Method for Reflectance Factor and Color by
1.4 Color difference units are calculated by the CIE 1976
Spectrophotometry Using Bidirectional (45°:0° or 0°:45°)
L*a*b* color difference equation.
Geometry
1.5 These test methods apply to colored artists’ materials. G24 Practice for Conducting Exposures to Daylight Filtered
Through Glass
1.6 The values stated in SI units are to be regarded as the
G113 Terminology Relating to Natural andArtificial Weath-
standard. The values given in parentheses are for information
ering Tests of Nonmetallic Materials
only.
G141 Guide for Addressing Variability in Exposure Testing
1.7 This standard does not purport to address all of the
of Nonmetallic Materials
safety concerns, if any, associated with its use. It is the
G151 Practice for Exposing Nonmetallic Materials inAccel-
erated Test Devices that Use Laboratory Light Sources
1
These test methods are under the jurisdiction of ASTM Committee D01 on
Paint and Related Coatings, Materials, and Applications and are the direct
2
responsibility of Subcommittee D01.57 on Artist Paints and Related Materials. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Dec. 1, 2022. Published December 2022. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1983. Last previous edition approved in 2016 as D4303 – 10 (2016). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.
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