Purpose of test This test simulates the effect of ultraviolet light and natural sunlight on various fabrics to make sure their color won’t change or fade in normal use. Terminology Defined Colorfastness — A fabric’s ability to retain color in various conditions. Xenon-Arc Lamp — A lamp that mimics natural sunlight by passing electricity through… Continue reading AATCC 16.3 Option 3 Colorfastness to Light: Xenon Arc