Which test is used to measure the colorfastness of fabrics?

The AATCC Test Method 61 is recognized specifically for assessing the colorfastness of textiles to laundering and other stresses. This method involves exposing the fabric to simulated washing conditions, allowing evaluators to determine how well the dye holds up under these circumstances. It yields a rating based on the degree of color change experienced by the fabric and any color transfer to adjacent materials, which is critical for ensuring that textiles maintain their intended appearance over time during normal consumer use.

Other methods mentioned, while they may pertain to various fabric properties, do not specifically target colorfastness in the same way that AATCC Test Method 61 does. For example, AATCC Test Method 20 focuses on the colorfastness to light, which is essential for determining how a fabric behaves when exposed to sunlight. Similarly, ASTM Test Method D5034 relates to the breaking strength and elongation of textiles, and ISO Test Method 105 covers various aspects of colorfastness but is broader in scope. Therefore, AATCC Test Method 61 is the most relevant test for evaluating colorfastness specifically concerning laundering conditions.