Color fastness to washing is a decisive quality indicator for printed textiles, revealing whether printed patterns and ground shades will fade, bleed, or stain adjacent fabrics during laundering. This technical guide explains how accredited third-party laboratories conduct printed textile washing fastness testing in accordance with ISO 105-C06, AATCC 61, GB/T 3921, and related standards, covering sample preparation, test conditions, grey scale grading, and typical acceptance criteria.
Technical Overview
Color fastness to washing (also called laundering fastness) measures the resistance of textile colors to detergent solutions under controlled temperature, time, and mechanical action. For printed textiles, the test evaluates two distinct failure modes: change in color (fading or shade alteration of the print and ground fabric) and staining (bleeding of color onto adjacent fabrics during the wash cycle).
Printed textiles are particularly vulnerable to washing damage. Pigment prints depend on a binder film that mechanically anchors pigment particles on the fiber surface, while reactive, disperse, and discharge prints require thorough post-print washing to remove unfixed dye and thickener residues. Incomplete curing, unbalanced binder formulations, or insufficient wash-off frequently result in poor wet fastness and cross-staining of other garments in domestic laundry.
The test principle is straightforward: a composite specimen, with the printed face placed against a multifiber adjacent fabric, is laundered in a standard detergent solution inside sealed stainless-steel canisters that rotate in a temperature-controlled water bath. After rinsing and drying, the specimen and the adjacent fabric are evaluated against grey scales, and results are expressed as grades from 1 (severe) to 5 (negligible), with permitted half-step ratings such as 4-5 and 3-4.
Testing Samples
Printed Fabric Specimens
For ISO 105-C06 and GB/T 3921 testing, a specimen of 100 mm x 40 mm is cut and sewn or clipped with the printed face in contact with a multifiber strip of the same size. For AATCC 61, a 50 mm x 100 mm specimen is used with an equivalent multifiber attachment. Because a print may contain multiple colors, specimens must be positioned so that every significant printed color contacts the adjacent fabric; large-motif prints often require duplicate composite specimens to cover all colors.
Printed Garments and Made-Up Articles
For finished goods such as printed T-shirts, dresses, bedding, and towels, representative swatches are cut from areas containing all printed colors. Where legally or contractually relevant, self-fabric trims, printed labels, and decorative patches may be tested as separate specimens.
Multifiber Adjacent Fabric
The adjacent fabric is a standardized multifiber strip containing six fiber components, typically wool, acrylic, polyester, nylon, cotton, and acetate (type DW) or an equivalent set in which viscose replaces wool (type TV). The selection between DW and TV follows the governing standard or the client specification, since wool can disproportionately absorb migrated dyes and bias staining results.
Sample Conditioning
Prior to final evaluation, dried specimens are conditioned in a standard atmosphere of 20 ± 2 °C and 65 ± 4 % relative humidity in accordance with ISO 139, ensuring consistent and reproducible grey scale assessment.
Testing Items
A standard washing fastness report for printed textiles typically includes the following assessment items:
- Color fastness to washing, change in color of the printed area (fading or shade change).
- Color fastness to washing, change in color of the ground fabric.
- Color fastness to washing, staining on each component of the multifiber adjacent fabric (bleeding and cross-staining potential).
- Optional variant tests: domestic laundering, commercial laundering, and laundering with chlorine or oxygen bleach where care-label claims or buyer protocols require them.
- Instrumental (spectrophotometric) grey scale values where objective, traceable measurement is required.
Grading follows a five-point scale: grade 5 means no visible change or staining, grade 3 indicates noticeable change or staining, and grade 1 represents severe change or staining. Half-step ratings are routinely reported for commercial precision.
Testing Methods
ISO 105-C06 / EN ISO 105-C06
The internationally recognized reference method specifies a family of test severities at 40 °C, 50 °C, 60 °C, 70 °C, and 95 °C, with washing times of 30 or 45 minutes and a liquor ratio of 50:1. Washing is performed with 4 g/L of ECE reference detergent (or standard soap), and selected severe methods additionally include sodium perborate. Mechanical action is standardized through stainless-steel balls: the "S" designation denotes no balls for sensitive fabrics, while "M" denotes ten balls for medium severity. A common choice for everyday printed apparel is the 40 °C, 30-minute method, which approximates a single domestic wash cycle.
AATCC 61
The North American accelerated laundering standard defines five conditions: Test 1A (40 °C, simulating hand washing with 10 steel balls), Test 2A (49 °C, simulating home laundering without bleach, 45 minutes with 50 steel balls, approximately equivalent to five home launderings), Test 3A (71 °C, heavy-duty commercial laundering), Test 4A (71 °C with sodium hypochlorite), and Test 5A (71 °C with oxygen bleach). Specimens are laundered in 200 mL of detergent solution in sealed canisters rotating at approximately 40 rpm in a controlled bath. Test 2A is the most frequently specified condition for printed garments sold in the United States and Canada.
GB/T 3921
The Chinese national standard is technically aligned with ISO 105-C06 and defines five soap-washing methods covering 40 °C to 95 °C. It is the mandated method for demonstrating compliance with GB 18401, the national general safety technical code for textile products, which sets minimum washing fastness requirements by product category.
JIS L 0844
The Japanese standard specifies comparable laundering fastness procedures using the same rotating-canister principle, and results are broadly comparable to ISO methods when test temperature, time, and ball count are matched.
Rating and Evaluation
Change in color is assessed using the grey scale in accordance with ISO 105-A02, while staining is assessed in accordance with ISO 105-A03. Instrumental grading is available through ISO 105-A05 and AATCC Evaluation Procedure 7, which convert colorimetric measurements into equivalent grey scale ratings. The reported result is the lowest grade recorded on any stained fiber component, and test reports must identify the exact method, temperature, duration, detergent, and ball count used.
Applications
Washing fastness testing of printed textiles supports quality assurance and compliance across the entire supply chain:
- Incoming inspection and lot acceptance of printed fabrics before cutting and garment production.
- Mandatory compliance demonstrations under national safety codes such as GB 18401 in China and equivalent regional requirements.
- Retailer and brand technical protocols, which typically stipulate minimum grades such as 3-4 or 4 for change in color and 3 or 3-4 for staining, with stricter limits for infant wear and adjacent-white designs.
- Research and development of print formulations, including binder systems, dye selection, fixation chemistry, and curing parameter optimization.
- Substantiation of care-label claims such as machine washability or bleach compatibility.
- Dispute resolution and root-cause analysis for consumer complaints involving fading, bleeding, or cross-staining after laundering.
Typical product categories include printed T-shirts and knitwear, dresses, children's wear, bedding sets, printed towels, home furnishing fabrics, and printed technical textiles.
FAQ
What grade is considered a pass for printed textiles?
Most buyer protocols and national standards require at least grade 3 for both change in color and staining, while many premium brands specify 3-4 or 4. Under GB 18401, infant products (category A) must achieve at least grade 3-4, whereas category B and C products require a minimum of grade 3. Specific limits always depend on the end use, the market, and the contractual specification.
Why does a print sometimes show lower fastness than the ground fabric?
Pigment prints fail mainly through binder degradation, under-curing, or over-application of print paste, while dye-based prints fail when unfixed dye and thickener residues are not adequately washed off after printing. In both cases, color migrates into the wash liquor and deposits on adjacent fibers during the test.
Should I choose ISO 105-C06 or AATCC 61?
Method selection is market-driven: ISO 105-C06 and its EN adoption dominate Europe and much of Asia, while AATCC 61 prevails in North America. As a rough correlation, AATCC Test 2A approximates an ISO 50 °C medium-severity method. Products distributed globally are commonly tested to both standards to satisfy all destination requirements.
How can poor washing fastness in prints be improved?
Effective corrective actions include optimizing binder content and crosslinking chemistry, verifying curing temperature and dwell time, intensifying post-print washing-off, applying suitable fixatives in dye-based systems, and selecting dyes or pigments with inherently high wet fastness properties.
How long does the test take?
The physical washing, rinsing, and drying cycle is completed within one working day, including conditioning and grey scale assessment. Accredited third-party laboratories typically issue a full report within three to five working days after sample receipt, subject to workload and any retesting.