Colorfastness to light

Colour Fastness to Light Testing as per ISO 105-B02 | Laboratory Analysis by METS Laboratories

Introduction

Exposure to sunlight and artificial light can cause textile colors to fade over time, affecting the appearance and quality of garments, home textiles, automotive fabrics, and outdoor products. Color fastness to light is therefore one of the most important durability assessments in the textile industry.

ISO 105-B02 is the internationally recognized standard used to determine the resistance of textile colors to artificial light exposure using a xenon arc lamp. Professional laboratories such as METS Laboratories perform ISO 105-B02 testing to help manufacturers evaluate color durability, comply with buyer requirements, and ensure product quality.

Laboratory Color Fastness to Light Testing

What is ISO 105-B02?

Textiles — Tests for Colour Fastness — Part B02: Colour Fastness to Artificial Light: Xenon Arc Fading Lamp Test

The standard specifies a method for determining the resistance of textile colors to artificial light that simulates natural daylight.

The test evaluates:

1. Color fading caused by light exposure 
2. Dye stability under UV radiation 
3. Resistance to sunlight simulation 
4. Long-term color durability 

This testing is widely used for:

1. Apparel textiles 
2. Home textiles 
3. Curtains and draperies 
4. Automotive interiors 
5. Outdoor fabrics 
6. Sportswear 
7. Technical textiles 

Importance of Color Fastness to Light Testing

ISO 105-B02 testing helps manufacturers:

1. Assess color durability 
2. Prevent premature fading 
3. Improve customer satisfaction 
4. Meet retailer and buyer specifications 
5. Support export compliance 
6. Maintain brand reputation 

Many international brands specify minimum light fastness requirements before approving products.

Principle of the Test

The textile specimen is exposed to controlled artificial light generated by a xenon arc lamp.

Blue wool reference standards are exposed simultaneously with the test specimen.

After exposure, the degree of fading is compared with the blue wool standards to determine the light fastness rating.

Xenon Arc Light Fastness Tester

The test equipment typically includes:

1. Xenon arc lamp 
2. Exposure chamber 
3. Temperature control system 
4. Humidity control system 
5. Blue wool reference standards 

The xenon arc lamp closely simulates natural daylight, including ultraviolet radiation.

Test Procedure

Sample Preparation

1. Textile specimens are cut according to standard requirements. 
2. Blue wool reference standards are mounted alongside the specimen. 
3. Samples are conditioned before testing. 

Light Exposure

The specimens are exposed to xenon arc light under controlled conditions of:

1. Irradiance 
2. Temperature 
3. Relative humidity 
4. Exposure duration 

Assessment

After exposure, laboratory specialists compare the color change of the specimen with the fading observed in blue wool standards.

Evaluation of Results

The degree of fading is assessed by comparing the specimen to the standard blue wool references.

Results are reported on a scale from:

Higher ratings indicate better resistance to light-induced fading.

Common Causes of Poor Light Fastness

Several factors may reduce light fastness performance:

1. Low-quality dyes 
2. Inappropriate dye selection 
3. High UV exposure 
4. Lack of UV stabilizers 
5. Certain bright shades and fluorescent colors 
6. Poor finishing treatments 

Proper dye selection and finishing processes can significantly improve light fastness.

Applications of Light Fastness Testing

ISO 105-B02 testing is commonly required for:

1. Fashion apparel 
2. Children's clothing 
3. Upholstery fabrics 
4. Curtains and draperies 
5. Automotive textiles 
6. Outdoor furniture fabrics 
7. Awnings and sunshades 

Products exposed to prolonged sunlight typically require higher light fastness ratings.

Benefits of ISO 105-B02 Testing

Manufacturers benefit from light fastness testing by:

1. Verifying product durability 
2. Meeting customer requirements 
3. Reducing fading complaints 
4. Supporting quality assurance programs 
5. Demonstrating compliance with international standards 
6. Enhancing consumer confidence 

Conclusion

ISO 105-B02 is a globally recognized standard for evaluating textile color fastness to artificial light exposure using a xenon arc fading lamp. Reliable testing helps manufacturers ensure long-lasting color performance, improve product quality, and meet international buyer expectations.

Professional laboratories such as METS Laboratories utilize calibrated xenon arc testing equipment, blue wool reference standards, and standardized procedures to provide accurate and dependable light fastness testing services.

As consumer expectations for durability and appearance continue to rise, color fastness to light testing remains an essential component of textile quality assurance and product performance evaluation.