The AATCC Test Method 163 – Colorfastness to Light: Xenon-Arc is a method used to measure the ability of textiles, colorants, finishes, and treatments to retain color when exposed to light. The test measures for both chromaticity and luminance with a spectrophotometer. Measurement is taken on an as-received sample, as well as a sample exposed to 40 AATCC Fading Units under a xenon-arc lamp. The lamp is intended to represent accelerated exposure to light, artificial and natural, in order to gain an understanding of the lifespan of high-visibility color of a textile.
To pass, the spectrophotometric values must fall within the coordinates listed in Table 3 of ANSI/ISEA 107 before and after the xenon-arc exposure. This assures the garment is safe to use in high-visibility safety apparel and accessories and will withstand conditions encountered during wear. Chromaticity and luminance are crucial to ensure the visibility of a garment and, hence, of a person wearing the garment.
Variations of the test can be performed based upon the intended use of the end product. ANSI/ISEA 107 defines the exposure required that best aligns with high-visibility safety apparel and accessories.