Color fading or color change due to exposure to light, heat, and moisture is a common issue for textiles, whether they are used outdoors or indoors. Since the 1960’s, xenon-arc testing has been the predominant method for assessing the color fastness of textiles under light exposure. All xenon-arc standard test methods involve exposure of small textile samples to controlled conditions of light, temperature, and humidity inside a specially designed xenon-arc test chamber.
Xenon-Arc Testing
When it comes to xenon-arc testing of textiles, we first need to explain two terms. The term light fastness (lightfastness) usually refers to indoor conditions that simulate natural sunlight behind window glass - no water spray included. For light fastness testing, the xenon-arc instrument must be fitted with optical window glass filters.
In contrast, the term weather fastness / weathering is always linked to outdoor conditions that simulate direct natural sunlight (daylight). Those tests involve water spray, except for tests that replicate dry desert or semi-arid conditions. For weathering testing, the xenon-arc instrument must be equipped with optical daylight filters.
Evaluating Test Results
Once the xenon-arc exposure is complete, test samples are assessed for color change. By using a set of standard blue wool reference materials during testing and a grey scale for comparison, the color stability of a material can practically expressed in numerical values between 1 and 8.
For certain textiles such as geotextiles, ropes, and seat belts, it is also essential to evaluate the changes in physical strength, such as tensile strength.
Top 15 Standards for Lightfastness and Weathering Testing of Textiles
There are many xenon standards for textiles, both national and international. The table lists the 15 most commonly used testing standards:
- 8 for lightfastness
- 7 for weathering.
More Information
To get the most out of your textile lightfastness or weathering testing, you find additional information online in our knowledge center and application overview These resources will help you understand the different xenon-arc test methods from sample preparation to evaluation for reliable and consistent results.
Download a free Atlas Guide on Xenon-Arc Weathering and Lightfastness Testing of Textiles or listen to a recorded online seminar on Colorfastness to Light Testing of Textiles.