Color Fastness Testing of Artificial Leather: Standards, Methods, and Quality Assessment

Color fastness testing of artificial leather is a critical quality control process that evaluates the resistance of dyed and coated synthetic leather materials to color loss, bleeding, and staining under various environmental conditions. This comprehensive guide covers the testing standards, sample types, testing items, and methods used by manufacturers, brands, and third-party laboratories to ensure artificial leather products meet international performance requirements for footwear, apparel, automotive, and furniture applications.

Technical Overview

Color fastness refers to the ability of a colored material to retain its original hue and to resist transferring color to adjacent materials when subjected to external influences such as rubbing, light exposure, perspiration, water, heat, and washing. For artificial leather—including PVC leather, polyurethane (PU) synthetic leather, and microfiber leather—color fastness is one of the most important performance indicators, because poor fastness leads to fading, staining of garments or car interiors, and visible degradation of the product surface.

Artificial leather differs fundamentally from textile fabric in its structure: the color is typically carried in a surface coating layer, a foamed middle layer, or a dyed microfiber substrate. As a result, color loss may occur not only through dye migration but also through coating abrasion, plasticizer bleeding, and binder breakdown. Professional color fastness testing therefore combines textile testing principles with leather-specific methods to provide a complete assessment of color durability.

Results are expressed using the Grey Scale, which ranges from grade 1 (severe color change or staining) to grade 5 (no visible change), with half-step increments such as 4–5. For light fastness, the Blue Wool Reference scale ranges from grade 1 (very poor) to grade 8 (outstanding). Testing is performed according to internationally recognized standards, including the ISO 105 series, AATCC test methods, ASTM standards, and regional leather material standards such as QB/T and EN specifications.

Testing Samples

PVC Artificial Leather

Polyvinyl chloride artificial leather is constructed from a fabric backing coated with a PVC plastisol layer. Because PVC relies heavily on plasticizers, this material is especially prone to color migration and plasticizer bleeding at elevated temperatures. Testing typically focuses on rub fastness, migration fastness, and heat resistance.

PU Synthetic Leather

Polyurethane synthetic leather features a PU coating applied to a textile or nonwoven base. It offers a softer hand feel and better flexibility than PVC. Key concerns include color fastness to rubbing, perspiration, and light, as the PU surface layer can hydrolyze and release pigments over time.

Microfiber Leather

Microfiber leather consists of ultra-fine fiber bundles impregnated with polyurethane and finished with a dyed surface. It closely resembles genuine leather and is widely used in premium applications. Testing emphasizes dye penetration, rub fastness, light fastness, and fastness to migration toward adjacent components.

Functional and Coated Variants

Samples may include solvent-free PU, bio-based leather, TPU film laminates, and surfaces with special finishes such as embossing, metallic effects, or printed patterns. These variants require tailored testing programs because printing inks and effect coatings often behave differently from conventional pigment systems.

Testing Items

A complete color fastness evaluation for artificial leather generally includes the following items:

• Color fastness to dry rubbing and wet rubbing
• Color fastness to artificial light (xenon arc) and to weathering
• Color fastness to perspiration (acid and alkaline)
• Color fastness to water and to seawater
• Color fastness to washing and dry cleaning
• Color fastness to migration (color transfer to PVC film, ABS, or other plastics)
• Color fastness to heat, sublimation, and hot pressing
• Color fastness to abrasion and coating adhesion related color loss
• Color fastness to ozone and atmospheric pollutants for specific applications

Testing Methods

Color Fastness to Rubbing

A crockmeter rubs a standardized white cotton cloth against the specimen under a fixed pressure of 9 N. For dry rubbing, the cloth is used as supplied and the finger completes 10 complete cycles; for wet rubbing, the cloth is wetted with distilled water to approximately 100% uptake. After rubbing, the degree of staining on the white cloth is evaluated with the Grey Scale for staining according to ISO 105-A03 or AATCC EP 2. Common standard references include ISO 105-X12, AATCC 8/116, and GB/T 3920. Typical acceptance criteria require grade 4 or higher for dry rubbing and grade 3 or higher for wet rubbing in general consumer goods.

Color Fastness to Light

Specimens are exposed to a controlled xenon arc light source alongside Blue Wool Reference fabrics under specified humidity and temperature conditions, following ISO 105-B02, AATCC 16, or GB/T 8427. Exposure continues for a defined number of hours or until a specified contrast is reached, after which the color change of the specimen is compared with the fading of the blue wool standards to assign a rating from 1 to 8. Automotive interior materials are commonly required to achieve grade 4.5 or higher due to prolonged sunlight exposure through windows.

Color Fastness to Perspiration

The specimen is sandwiched between adjacent multifiber fabric, immersed in an artificial perspiration solution (alkaline and acidic variants), placed between acrylic plates, and kept in an oven at 37 °C for 4 hours, in accordance with ISO 105-E04 or GB/T 3922. Both the color change of the specimen and the staining of the adjacent fabric are assessed using Grey Scales. This test is essential for footwear linings, sportswear trim, and accessories in direct skin contact.

Color Fastness to Migration

Migration testing is particularly significant for artificial leather used alongside plastics, such as white PVC components in footwear or car interior trim. The colored specimen is placed in intimate contact with a white PVC film or other target substrate under a specified pressure and exposed to a set temperature—commonly 50 °C to 80 °C—for periods ranging from 3 to 16 hours. The staining on the receiving substrate is then rated using the Grey Scale for staining. Typical standards include QB/T 2925 and customer-specific protocols from footwear and automotive brands.

Color Fastness to Water and Washing

For water fastness, the specimen and adjacent fabric are immersed in water, drained, and pressed between plates at 37 °C for 4 hours per ISO 105-E01. Washing fastness is evaluated by laundering the specimen in a standard solution under defined temperature and agitation conditions and rating both color change and staining. These tests are critical for washable garment trims, bags, and home textile applications.

Applications

Color fastness testing of artificial leather supports quality assurance and regulatory compliance across a wide range of industries:

• Footwear: uppers, linings, and insole boards to prevent sock and foot staining
• Automotive interiors: seat covers, door panels, dashboards, and steering wheel wraps subjected to intense sunlight and heat
• Furniture upholstery: sofas and chairs requiring resistance to daily abrasion and cleaning
• Bags, belts, and leather goods: color stability against clothing and hardware contact
• Apparel and trim materials: washable garments, sportswear, and garment accessories
• Consumer electronics and packaging: synthetic leather cases and covers requiring migration resistance
• Export compliance: meeting buyer specifications, REACH-related colorant requirements, and international trade contracts

FAQ

What is a passing grade for color fastness in artificial leather?

Acceptance levels depend on the product category and buyer specification. In general consumer products, dry rubbing fastness of grade 4 or above and wet rubbing fastness of grade 3 or above are widely accepted. Premium and automotive applications frequently demand higher ratings, such as grade 4–5 for rub fastness and grade 4.5 or above for light fastness.

How are grey scale ratings interpreted?

The Grey Scale runs from 1 to 5, where 5 means no perceivable color change or staining and 1 indicates severe change or staining. Intermediate half grades, such as 3–4, allow finer discrimination. Grade 4 or higher is generally regarded as commercially acceptable for most applications.

How should specimens be prepared before testing?

Specimens should be conditioned in a standard atmosphere—typically 20 °C and 65% relative humidity—for at least 24 hours prior to testing. Samples must be free from wrinkles, taken from representative production material, and cut to the dimensions required by each method, commonly 50 mm by 140 mm for rubbing tests.

Why does artificial leather sometimes fail migration testing?

Migration failures usually stem from excessive plasticizer content, poorly fixed pigments, low-molecular-weight dye components, or inadequate crosslinking in the topcoat. Heat accelerates the movement of these substances into adjacent materials, which is why migration tests are conducted at elevated temperatures that simulate real storage and use conditions.

How long does a complete color fastness test program take?

Basic rub and water fastness tests can be completed within one to three working days. Light fastness testing is the most time-consuming, as exposure may run from 20 hours for low-requirement items to more than 100 hours for automotive-grade materials, extending the total turnaround to one to two weeks.