Colorfastness to Light

 

The purpose of this test is to determine how much the color will fade when exposed to a known light source. The proper test method is AATCC Test Method 16. Option A uses a Carbon Arc light source while Option E uses the more popular Xenon light source. The option used will depend on the equipment available. The test duration will be 10 AATCC fade units minimum for both colors and whites unless otherwise specified. Ten AATCC fade units are the equivalent to 2.5 to 3 continuous twenty four hour days of direct sunlight while 20 AATCC fade units are equivalent to 5-6 days of direct sunlight.

     The evaluation will be done as described in the test method with the exception of whites. Whites will be evaluated with the AATCC Gray Scale for Staining because the issue is more often yellowing of the white color.