This part of ISO 105 specifies a method for determining the colour fastness and ageing properties of all kinds and forms of dyed and printed textiles and/or other organic substrates under the action of an artificial light source representative of natural daylight (D65), and under the simultaneous action of heat. Of the four different sets of exposure conditions specified (see 6.1), three use D65, and the fourth a somewhat lower cut-off wavelength. The test method gives special consideration to the light and heat conditions that occur in the interior of a motor vehicle. The four different sets of conditions specified are known to give similar but not necessarily identical results.