ASTM D 4303 : 2010 : R2022

1.1Four 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.

1.2These 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.

1.3Lightfastness categories are established to which colorants are assigned based on the color difference between specimens before and after exposure.

1.4Color difference units are calculated by the CIE 1976 L*a*b* color difference equation.

1.5These test methods apply to colored artists’ materials.

1.6The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.7This 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.

1.8This 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.