Results of a recent study clearly indicate that the carbon arc FadeOmeter is not a reliable instrument for obtaining precision results and its use can lead to erroneous conclusions in lightfastness testing. Investigations show there is a serious variation in the degree of fade from the topto the middle to the bottom of the samples mounted in the specimen holder. There is an equally serious variation in the degree of fade depending on the position of the specimen holder in the revolving rack of the Fade-Ometer during simultaneous exposures. There is also a wide variation in the degree of fade from cycle to cycle of samples mounted in the same vertical and rack position of the Fade-Ometer. -- AATA