The AATCC 125-2004 standard is used to determine the colour fastness of stained Spinning & weaving products in sweat-stained solutions and under light conditions. Test samples are first immersed in sweat-stained solutions and then exposed to the sun in a light fastness meter. The standard provides detailed operating procedures and test conditions, including the use of Xenon-arc lamps for light testing and the use of AATCC grey sample cards for the evaluation of colour change. Test results are reported in colour change grades and recommended instruments and materials are also listed to ensure the accuracy of the test.