1. Purpose and Scope

1.1 This test method provides the general principles and procedures which are currently in use for determining the colorfastness to light of textile materials. The test options described are applicable to textile materials of all kinds and for colorants, finishes and treatments applied to textile materials. Test Options included are:

1-Enclosed Carbon-Arc Lamp, Continuous Light

2-Enclosed Carbon-Arc Lamp, Alternate Light and Dark

3-Xenon-Arc Lamp, Continuous Light, Black Panel Option

4-Xenon-Arc Lamp, Alternate Light and Dark

5-Xenon-Arc Lamp, Continuous Light, Black Standard Option

6-Daylight Behind Glass

1.2 The use of these test options does not imply, expressly or otherwise, an accelerated test for a specific application. The relationship between any lightfastness test and the actual exposure in use must be determined and agreed upon by the contractual parties.

2. Principle

2.1 Samples of the textile material to be tested and the agreed upon comparison standard(s) are exposed simultaneously to a light source under specified conditions. The colorfastness to light of the specimen is evaluated by comparison of the color change of the exposed portion to the masked control portion of the test specimen or unexposed original material, using the AATCC Gray Scale for Color Change or by instrumental color measurement. Lightfastness classification is accomplished by evaluation versus a simultaneously exposed series of AATCC Blue Wool Lightfastness Standards.