Color fastness determination is a critical quality control procedure for evaluating the resistance of dyed and printed fabrics to fading, bleeding, and staining during use, laundering, and environmental exposure. This comprehensive technical guide covers the principle, sample types, testing items, international test methods, and practical applications of color fastness testing for dyed textiles. Whether you are a textile manufacturer, quality engineer, or sourcing professional, understanding these standardized procedures based on ISO, AATCC, GB, EN, and JIS standards is essential for ensuring product compliance and consumer satisfaction.
Technical Overview
Color fastness refers to the resistance of a dye or print on a textile substrate to color change or color transfer when the material is subjected to various environmental, mechanical, and chemical influences such as washing, rubbing, perspiration, light exposure, dry cleaning, and chlorinated water. The determination of color fastness of dyed fabrics is one of the most fundamental and widely performed tests in textile quality assurance, as poor fastness directly affects the appearance, durability, and safety of finished textile products.
Color fastness is typically assessed in two dimensions: color change (fading or alteration of the original shade on the tested specimen) and staining (transfer of color onto adjacent materials such as multifiber adjacent fabrics or undyed cotton). Results are expressed on a gray scale rating from 1 (very poor) to 5 (excellent), where grade 5 indicates negligible change or staining and grade 1 indicates severe change or staining. For light fastness, ratings extend from 1 to 8 using blue wool reference standards, with grade 8 representing the highest resistance to fading.
The test methodology is governed by an internationally harmonized family of standards, principally the ISO 105 series, along with the AATCC test methods widely used in North America, the GB/T standards applied in China, and the JIS L 0800 series used in Japan. Although the procedural details differ slightly between these systems, the underlying principles—controlled specimen preparation, defined exposure conditions, and instrumental or visual rating against calibrated references—remain consistent. Accredited third-party laboratories routinely perform these tests for product certification, regulatory compliance, and buyer acceptance in global trade.
Testing Samples
Dyed and Printed Woven Fabrics
Woven fabrics in piece-dyed, yarn-dyed, or printed form constitute the most common sample category. Specimens are cut to the dimensions specified by the relevant method, typically 40 mm × 100 mm for washing and perspiration tests or 50 mm × 140 mm for rubbing tests, and are backed with adjacent fabrics to capture any staining that occurs during the test.
Knitted Fabrics
Knitted fabrics, including jersey, rib, and interlock constructions used in T-shirts, underwear, and sportswear, are tested using the same principles. Because of their elasticity, knitted specimens are usually mounted on rigid backing cards before crocking tests to prevent dimensional distortion and ensure reproducible rubbing contact.
Yarns and Dyed Fibers
Colored yarns can be assessed by winding them onto a suitable frame, knitting it into a small swatch, or laying parallel lengths between adjacent fabrics so that a test surface of adequate area is formed. This approach is common for evaluating dyed yarn lots before weaving or knitting.
Finished Garments and Components
Complete garments, trims, labels, sewn threads, zippers, and coated or laminated components may be tested directly to verify the fastness of the assembled product. Testing at the garment stage helps identify compatibility issues between differently colored panels, such as contrast collars, piping, and embroidery threads.
Specialty and Technical Textiles
Automotive interior fabrics, military and workwear textiles, outdoor and marine fabrics, and home furnishing materials such as upholstery and curtain fabrics require fastness verification under more demanding conditions, including high-temperature light exposure and abrasion combined with perspiration.
Testing Items
Depending on the end use of the dyed fabric and the requirements of the buyer or target market, one or more of the following fastness properties are determined:
- Color fastness to domestic and commercial laundering (ISO 105-C06, GB/T 3921, AATCC 61)
- Color fastness to rubbing, both dry and wet (ISO 105-X12, GB/T 3920, AATCC 8, JIS L 0849)
- Color fastness to artificial light using xenon arc lamp (ISO 105-B02, GB/T 8427, AATCC 16)
- Color fastness to perspiration, acidic and alkaline (ISO 105-E04, GB/T 3922, AATCC 15)
- Color fastness to water immersion (ISO 105-E01, GB/T 5713)
- Color fastness to sea water (ISO 105-E02, GB/T 5714)
- Color fastness to chlorinated swimming pool water (ISO 105-E03, GB/T 8433)
- Color fastness to dry cleaning with perchloroethylene (ISO 105-D01, GB/T 5711)
- Color fastness to sublimation and heat pressing (ISO 105-X11, GB/T 6152, GB/T 5718)
- Color fastness to hypochlorite and peroxide bleaching (ISO 105-N01/N02)
- Color fastness to potting, decatizing, and other wet processing operations (ISO 105-E08 to E12)
- Color fastness to saliva, particularly for infant and toddler products (DIN 53160, GB/T 18886)
Each test result is reported separately for color change and for staining on each component of the multifiber adjacent fabric, providing a complete fastness profile of the dyed material.
Testing Methods
Specimen Preparation and Adjacent Fabrics
Specimens are conditioned in a standard atmosphere, normally 20 ± 2 °C and 65 ± 4 % relative humidity, before testing. A piece of multifiber adjacent fabric (containing bands of wool, acrylic, polyester, nylon, cotton, and acetate, or a second composition depending on the standard version) is placed in direct contact with the face of the specimen. The composite specimen is then subjected to the specific test condition, after which the specimen is dried and evaluated.
Color Fastness to Washing
In the ISO 105-C06 procedure, the composite specimen is agitated in a wash liquor containing a standard detergent, with or without sodium perborate and ballast fabric depending on the severity selected, at temperatures ranging from 40 °C to 60 °C for durations of 30 to 45 minutes in a rotating wash wheel. After rinsing and drying, the gray scale ratings for color change and staining are determined. The AATCC 61 method follows a similar logic with its own liquor ratio and detergent specifications, typically using 2A or 5A test conditions for comparison with five domestic launderings or five commercial launderings respectively.
Color Fastness to Rubbing
The crockmeter test measures the transfer of surface color through mechanical action. A white cotton rubbing cloth, dry for the dry test and soaked in distilled water at 100 % pick-up for the wet test, is mounted on a finger that rubs the specimen along a 104 mm track for 10 cycles under a 9 N force. The degree of staining on the cotton cloth is rated using the gray scale for staining. Wet rubbing fastness is usually the more demanding parameter and is frequently the limiting specification for dark shades dyed with reactive, sulfur, or indigo dyes.
Color Fastness to Light
Specimens and a set of blue wool reference fabrics are exposed simultaneously in a xenon arc apparatus under controlled irradiance, black panel temperature, humidity, and filtration that simulates daylight through window glass. Exposure is terminated after a defined number of blue wool fading units or radiant energy, and the degree of fading is compared with the blue wool references to assign a rating from 1 to 8. This test is essential for curtains, automotive textiles, and outdoor products, and instrumental measurement using spectrophotometric color difference is increasingly applied in accordance with ISO 105-A05 for greater objectivity.
Color Fastness to Perspiration
Two composite specimens are prepared, one immersed in an acidic solution (histidine monohydrochloride monohydrate, sodium chloride, and disodium hydrogen orthophosphate at pH 5.5) and one in an alkaline solution at pH 8.0. After complete wetting, the composites are placed between acrylic plates under a 5 kg load in a perspirometer and kept at 37 °C for 4 hours, then dried and rated for color change and staining. This test is mandatory for most garments in contact with skin and is particularly important for sportswear and underwear.
Color Fastness to Water, Sea Water, and Chlorinated Water
For water and sea water fastness, the composite specimen is soaked in distilled water or a sodium chloride solution, respectively, then pressed and held in the perspirometer at 37 °C for 4 hours. For chlorinated water, the specimen is treated in a dilute sodium hypochlorite solution (typically 50 mg/L or 20 mg/L available chlorine, pH 8.5) at 27 °C with agitation, after which color change is assessed. Swimwear and products intended for pool environments require this test.
Color Fastness to Dry Cleaning
The specimen, enclosed in a bag with cotton ballast and stainless steel discs, is agitated in tetrachloroethylene in a sealed, mechanically rotated cage at 30 °C for 30 minutes, then dried and evaluated for color change, staining, and any delamination or coating damage.
Color Fastness to Heat and Sublimation
Dry pressing, damp pressing, and wet pressing tests contact the specimen with a heated plate at 110 °C, 150 °C, or 200 °C for 15 seconds, while sublimation tests expose the composite specimen to dry heat at 150 °C to 210 °C for 30 seconds to several hours. These methods evaluate thermomigration of disperse dyes, which is critical for polyester-containing fabrics and their blends.
Rating and Instrumental Assessment
Visual assessment is performed in a color matching cabinet under D65 illumination with the gray scale for color change (ISO 105-A02 / GB/T 250) and the gray scale for staining (ISO 105-A03 / GB/T 251). To improve reproducibility, instrumental methods based on spectrophotometer measurements convert the color difference between treated and untreated specimens into fastness grades according to ISO 105-A04 and ISO 105-A05. Test reports must state the specific method, condition, temperature, and adjacent fabric used, since ratings are only comparable within the same protocol.
Applications
Color fastness determination serves multiple purposes across the textile value chain, from raw material qualification to final product acceptance:
- Quality control of dyeing and finishing processes, enabling dyehouses to verify fixation, washing-off efficiency, and recipe suitability before bulk production
- Compliance with national mandatory standards and product labeling regulations, such as GB 18401 and GB 31701 in China and the general product safety framework in the European Union
- Eco-label and buyer protocol conformity, including OEKO-TEX and retailer-specific performance specifications that define minimum fastness grades by product category and shade depth
- Dispute resolution and claims analysis, where accredited third-party laboratories provide neutral test reports for commercial settlements between suppliers and buyers
- Product development of high-performance textiles, such as light-fast automotive interiors, chlorine-resistant swimwear, and perspiration-resistant athletic apparel
- Research and development of new dyes, auxiliaries, and fixing agents, where comparative fastness profiles guide formulation improvements
FAQ
What is a passing grade for color fastness?
Acceptance criteria depend on the product category, target market, and applicable standard. As a general guideline, many buyer protocols require a minimum of grade 4 for color change and grade 3–4 for staining in washing and perspiration tests, and grade 3 for wet rubbing on dark shades. Light fastness requirements commonly range from grade 4 to grade 6 for general apparel and grade 6 or higher for outdoor and automotive applications. Always confirm the specification with the relevant regulation or purchase contract.
Why does the same fabric receive different grades under ISO and AATCC methods?
Although both systems use similar hardware, they differ in detergent composition, liquor ratios, temperatures, and adjacent fabric constructions. These differences can shift results by half a grade or more, so test reports must always identify the exact method applied, and comparisons should only be made within a single standard system.
What causes poor wet rubbing fastness and how can it be improved?
Poor wet rubbing fastness is usually caused by insufficient dye fixation, inadequate washing-off of hydrolyzed or unfixed dye, excessive surface dye concentration in deep shades, or poor dye selection for the fiber. Corrective measures include optimizing the dyeing recipe and alkali dosage, strengthening soaping with appropriate washing-off auxiliaries, applying cationic fixing agents, and reducing surface dye through improved rinsing sequences.
Can color fastness results be measured instrumentally instead of visually?
Yes. Spectrophotometric measurement combined with the calculation rules in ISO 105-A04 and ISO 105-A05 converts color difference values into fastness grades, reducing operator subjectivity. Instrumental assessment is particularly useful for borderline ratings and for laboratories seeking improved repeatability, although the test conditions themselves remain defined by the exposure standards.
How long does a typical color fastness test take?
Washing, rubbing, perspiration, water, and dry cleaning tests are typically completed within one working day including conditioning and rating. Light fastness testing is the exception: depending on the required exposure level, xenon arc tests may run from a few hours to several days, so light fastness should be scheduled early in any testing program.
Which fastness tests are mandatory for children's textile products?
Most regulatory regimes for infants' and children's products place particular emphasis on fastness to saliva, perspiration, and water, in addition to washing and rubbing, because of the likelihood of prolonged skin and mouth contact. Requirements such as GB 31701 in China specify minimum grades for these properties, and accredited third-party laboratories can confirm the exact test package applicable to the destination market.