Light fastness shows how quickly a colour fades under light exposure, tested on a blue wool scale from 1 to 8, usually with a xenon lamp (ISO 105-B02). For indoor clothing, grade 4 is usually enough. For garments worn outdoors a lot, or for items exposed to the sun, grade 5 or higher is asked for.
Brights, pastels and some intense colours can score lower. Do not confuse fading by light with fading by washing. Ask for both grades if the product will be displayed for long periods or worn in strong sun.
light-fastnessiso-105-b02fading
