ISO 105-C06 Textile Color Fastness to Washing Testing

Introduction 

Color fastness to washing is one of the most important quality parameters in the textile industry. Textile products are repeatedly exposed to washing during consumer use, and poor wash fastness can result in fading, color bleeding, staining, and reduced garment appearance. 

International Organization for Standardization ISO 105-C06 is the internationally recognized testing standard used to evaluate the resistance of textile colors to domestic and commercial laundering. 

Professional textile laboratories such as METS Laboratories perform ISO 105-C06 testing to support global quality standards, retailer requirements, and export compliance. 

What is ISO 105-C06? 

ISO 105-C06 is titled: 

Textiles — Tests for colour fastness — Part C06: Colour fastness to domestic and commercial laundering 

This method determines the resistance of textile colors to washing under controlled laboratory conditions.

The test evaluates: 

• Color change of the textile specimen 
• Staining on adjacent fabrics 
• Dye durability after washing 
• Fabric appearance after laundering 

The standard is widely applied to: 

• Apparel textiles 
• Sportswear 
• Home textiles 
• Children’s garments 
• Workwear 
• Fashion fabrics 

Importance of Wash Fastness Testing 

ISO 105-C06 testing helps manufacturers: 

• Ensure product durability 
• Prevent color bleeding during washing 
• Improve customer satisfaction 
• Meet buyer quality requirements 
• Reduce product complaints 
• Maintain brand reputation 

Many international brands require wash fastness testing before approving textile products. 

Laboratory Equipment Used in ISO 105-C06 

Launderometer Testing Equipment 

Professional laboratories use specialized equipment including: 

• Launderometers 
• Stainless steel washing containers 
• Multifiber adjacent fabrics 
• Standard detergents 
• Grey scale assessment systems 
• Drying ovens and conditioning chambers 

These instruments simulate domestic and commercial laundering conditions accurately. 

 Washing Process 

The specimen is placed in a laundering container with: 

• Standard detergent solution 
• Stainless steel balls (for mechanical action) 
• Controlled water temperature 

The washing cycle simulates: 

• Domestic laundering 
• Commercial washing conditions 
• Mechanical agitation 
• Thermal exposure 

 Rinsing and Drying 

After washing, the specimen is:

• Rinsed thoroughly 
• Dried under controlled conditions 
• Conditioned before evaluation 

This process ensures standardized result interpretation. 

4. Evaluation of Results 

Laboratory experts assess: 

• Color change of the original specimen 
• Staining on adjacent fabrics 

Evaluation methods include: 

• Grey scale ratings 
• Instrumental color measurement 
• Visual assessment under standard lighting 

Grey Scale Rating System 

ISO 105-C06 commonly uses a grey scale rating from: 

Rating          Performance

1           Poor wash fastness 

5           Excellent wash fastness 

Higher ratings indicate better resistance to laundering. 

Common Causes of Poor Wash Fastness 

Several factors may reduce washing fastness performance: 

• Poor dye fixation 
• Excess unfixed dyes 
• Low-quality dye chemicals 
• Inadequate washing after dyeing 
• Incorrect dyeing parameters 

Optimized dyeing and finishing processes improve wash durability. 

Conclusion 

ISO 105-C06 is an essential textile testing standard for evaluating color fastness to washing. Reliable wash fastness testing helps manufacturers ensure product durability, reduce customer complaints, and comply with international buyer requirements. 

Professional laboratories such as METS Laboratories use advanced laboratory equipment and internationally recognized methods to provide accurate and dependable textile testing services. 

As textile quality expectations continue to rise globally, wash fastness testing remains a critical component of textile product performance evaluation and quality assurance.