ASTM D4303-99 - 10.5.1999
 
1. Scope

1.1 Three test methods consisting of exposure to light (natural sunlight or simulated sunlight) filtered through glass are described as follows:

1.1.1 Test Method A -Exposure under glass to the sun,

1.1.2 Test Method B -Exposure to irradiance from artificial daylight fluorescent lamps, and

1.1.3 Test Method C -Exposure in xenon-arc lightfastness apparatus.

1.2 These test methods are used to approximate the color change that can be expected over time in pigments used in artists' paints in normal indoor exposure.

Note 1-The color changes that result from accelerated exposure may not duplicate the results of normal indoor exposure in a home or gallery. The relative resistance to change, however, can be established so pigments can be assigned to categories of relative lightfastness.

1.3 Lightfastness categories are established to which pigments 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 artists' oil, resin-oil, acrylic emulsion, alkyd, and watercolor paints.

1.6 This standard does not purport to address the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

 
2. Referenced Documents

D2244-25

Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates

D4674-25

Standard Practice for Accelerated Testing for Color Stability of Plastics Exposed to Indoor Office Environments

G155-25

Standard Practice for Operating Xenon Arc Lamp Apparatus for Exposure of Materials

D5067-16(2021)

Standard Specification for Artists´ Watercolor Paints

D5098-16(2021)

Standard Specification for Artists´ Acrylic Dispersion Paints

D5724-16(2021)

Standard Specification for Gouache Paints

D6901-15(2021)

Standard Specification for Artists' Colored Pencils

E284-25

Standard Terminology of Appearance

D4302-14(2021)

Standard Specification for Artists’ Oil, Resin-Oil, and Alkyd Paints

E1349-06(2022)

Standard Test Method for Reflectance Factor and Color by Spectrophotometry Using Bidirectional (45?:0? or 0?:45?) Geometry

G24-21

Standard Practice for Conducting Exposures to Daylight Filtered Through Glass

G113-24

Standard Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials

E1347-06(2020)

Standard Test Method for Color and Color-Difference Measurement by Tristimulus Colorimetry

E1348-22

Standard Test Method for Transmittance and Color by Spectrophotometry Using Hemispherical Geometry

G141-09(2021)

Standard Guide for Addressing Variability in Exposure Testing of Nonmetallic Materials

G151-26

Standard Practice for Exposing Materials in Accelerated Test Devices that Use Laboratory Light Sources