Standard Test
International testing standards provide the protocols necessary to evaluate the relative whiteness of textile materials under controlled laboratory conditions. The standard known as ISO 105-J02 defines the method for calculating whiteness and tint using spectrophotometric data. It is the global benchmark for verifying that bleached fabrics meet the brightness requirements specified by apparel brands.
This standard ensures that factories in different countries use the same mathematical models to evaluate their output.
Instrumental Requirements
Implementing the standard requires a spectrophotometer equipped with a controllable ultraviolet light source. Under ISO 105-J02, the instrument must be calibrated using a reference standard to ensure that the ultraviolet component of the light remains constant over time. This calibration is necessary because the intensity of the UV light directly affects how fluorescent whitening agents react during the test.
Consistent instrument setup prevents discrepancies in whiteness values when samples are tested by different laboratories.
Sample Preparation
Fabric specimens must be folded or layered to ensure they are completely opaque before being placed against the measurement port.
Supply Verification
Garment buyers rely on these standardized whiteness numbers to approve fabric lots before they are cut and sewn into finished products. Discrepancies in whiteness are a common cause of assembly line delays and finished product rejection. By requiring suppliers to conform to the measurements outlined in this international standard, brands reduce the risk of receiving mismatched components.
This objective verification replaces subjective visual assessments that can vary due to lighting conditions or human eye fatigue.
