Colorfastness Tests for Textiles: Guide to Colorfastness Test Methods
The multitude of colorfastness tests for textiles can make it difficult to determine which methods are most suitable for your products. However, without the proper testing protocol, you risk selling items that lose their color over time.
This article explains the various testing options to provide you with a thorough understanding of colorfastness testing. You’ll get the details on the main colorfastness test methods and standards, including the applicability and benefits of each, so you can ensure your textiles meet quality standards.
Colorfastness Testing: Why It Matters and How It Works
Colorfastness refers to the resistance of a fabric to fade or bleed its color when subjected to various environmental conditions such as washing, light exposure, perspiration, and friction. It is a critical quality attribute for textiles, ensuring that the colors remain vibrant and true throughout the product's life.
Adhering to industry standards for colorfastness is vital for marketability and customer satisfaction. Two key organizations that set these standards are:
ISO (International Organization for Standardization): ISO standards, such as the ISO 105 series, provide guidelines for various colorfastness tests, ensuring consistency and reliability in testing methods worldwide.
AATCC (American Association of Textile Chemists and Colorists): The AATCC develops standardized test methods, including those for colorfastness, which are widely recognized and used in the textile industry.
Colorfastness Rating System
The ability of a fabric to resist fading or running is determined by a straightforward grading system on a scale of 1 to 5:
Grade 5: Indicates the highest quality with excellent resistance to fading or bleeding.
Grade 1: Indicates the lowest quality with poor resistance to fading or bleeding.
This uniform grading system applies to all textile products, regardless of the specific colorfastness criteria they are measured against. By maintaining a consistent rating system, manufacturers and quality assurance managers can easily assess and compare the colorfastness of different fabrics.
What Are the Key Colorfastness Test Methods and Standards?
There are a variety of colorfastness test methods designed to measure the fabric’s ability to resist fading when exposed to specific conditions and reagents, from light to human sweat. The following test methods are among the most commonly used, but the list below is not exhaustive.
Colorfastness to Washing
Colorfastness to washing tests measure a fabric's ability to retain its color after being subjected to laundering. This test evaluates the effects of domestic or commercial washing processes on the fabric's color. The colorfastness to washing test is essential for a wide range of textile products, particularly those that undergo frequent laundering like apparel, home textiles like bed linens, or hospital textiles.
The primary standard for colorfastness to washing is ISO 105-C06:2010, which uses a reference detergent to simulate normal household washing conditions.
Two types of tests are conducted:
Single (S) Test: Represents one commercial or domestic wash cycle, assessing color loss and staining due to desorption and abrasive action.
Multiple (M) Test: Simulates up to five commercial or domestic wash cycles, using increased mechanical action to represent more severe laundering conditions.
The test involves washing fabric samples under specified conditions (temperature, detergent concentration, and mechanical action), followed by evaluating the color loss and staining on adjacent fabrics.
Colorfastness to Light
Colorfastness to light tests measure a fabric's ability to maintain its color when exposed to light. This test evaluates the effects of natural and artificial light sources on the fabric's color, ensuring the durability and longevity of textiles that are regularly exposed to light. This test applies to many textile products but is especially important for those that are frequently exposed to light, such as outdoor clothing, home textiles like curtains or outdoor furniture fabrics, or automotive textiles.
The primary standards for colorfastness to light are ISO 105-B01:2014 and ISO 105-B02:2014:
ISO 105-B01:2014 specifies a method for determining the resistance of textile colors to the action of daylight. It involves the use of two different sets of blue wool references, which serve as benchmarks for comparing the test results. In the test, fabric samples are exposed to daylight under controlled conditions. The color change is then evaluated against the blue wool references.
Similarly, ISO 105-B02:2014 specifies a method for determining the effect of artificial light sources, representative of natural daylight (D65), on textile colors. In this test, the fabric samples are exposed to a xenon arc lamp, rather than natural daylight. A similar test method is also described in AATCC 16.3.
Colorfastness to Rubbing
Colorfastness to rubbing tests measure a fabric's ability to resist color transfer from the surface of the textile to another surface through friction. This test is essential for ensuring that textiles do not bleed or stain other materials when subjected to rubbing, which is particularly important for items like apparel, upholstery, and textile floor coverings.
The primary standard for colorfastness to rubbing is ISO 105-X12:2016. This standard specifies a method for determining colorfastness to rubbing by rubbing a standard white cloth against the textile sample under controlled conditions. The degree of staining on the white cloth is then assessed and rated to determine the fabric's colorfastness to rubbing.
Two types of tests are conducted:
Dry Rubbing Test: A dry rubbing cloth is used to assess the color transfer from the textile when dry.
Wet Rubbing Test: A wet rubbing cloth is used to evaluate the color transfer when the textile is wet.
Colorfastness to Perspiration
Colorfastness to perspiration tests measure a fabric's ability to maintain its color when exposed to human sweat. This test is critical for textiles that come into direct contact with the skin, such as activewear, undergarments, and other apparel.
The primary standards for colorfastness to perspiration are ISO 105-E04:2013 and AATCC 15.
ISO 105-E04:2013 involves treating specimens of the textile in contact with adjacent fabrics in two different solutions containing histidine, an amino acid found in sweat. The specimens are drained, placed between two plates under a specified pressure in a test device, and dried separately. The change in color of each specimen and the staining of the adjacent fabrics are assessed by comparison with gray scales or instrumentally.
AATCC 15 determines the fastness of colored textiles to the effects of acid perspiration. It applies to dyed, printed, or otherwise colored textile fibers, yarns, and fabrics of all kinds. In this test, a textile specimen is placed in contact with other fiber materials to assess color transfer. The specimen is wet in a simulated acid perspiration solution, is allowed to dry slowly, and is then evaluated for color change and color transfer.
Colorfastness to Seawater
Colorfastness to seawater tests measure a fabric's ability to retain its color when exposed to seawater. This test is essential for textiles frequently in contact with seawater, such as swimwear, beachwear, and marine textiles.
The primary standard for colorfastness to seawater is ISO 105-E02:2013. The test involves attaching the textile specimen to adjacent fabrics, immersing them in a sodium chloride solution for 30 minutes, and then draining and pressing it under 12.5 kPa pressure. The specimen is then heated in an oven at 37°C for four hours and dried separately. Finally, the color change and staining are evaluated.
Colorfastness to Chlorinated Water
Colorfastness to chlorinated water tests measure a fabric's ability to maintain its color when exposed to chlorinated water, commonly found in swimming pools. This test is crucial for textiles frequently used in chlorinated environments, such as swimwear, beach robes, and towels.
The primary standard for colorfastness to chlorinated water is ISO 105-E03:2010. The test involves immersing textile specimens in chlorinated water at concentrations of 50 mg/l or 100 mg/l for swimwear, and 20 mg/l for accessories like beach robes and towels. After exposure, the specimens are evaluated for color change and staining using gray scales or instruments.
Ensure Colorfastness with QIMA
QIMA provides comprehensive textile testing services and can help you determine the most important tests for your specific textile product types. With our expertise, you can confidently assure the quality and longevity of your textiles, enhancing your brand reputation and customer trust.
Learn more about our textile testing services or contact us today to book a test.
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