Abstract:
Colour fastness is an important property of industrial products. Traditionally, the colour fastness can be rated through visual assessment by using two grey scales. One is for change in colour and the other is for staining. While the instrumental measurement methods seem to play an important role. In this research, the available colour fastness formulae used in industries were reconsidered through Thai visual assessments. These formulae include CIELAB, CMC (I:c), ISO, Nc# and Fc. The relationship between instrumental and the visual assessment was analysed. The obtained result shows that, the correlation coefficient for ISO standard gives the highest correlation coefficient at 0.941, whereas other formulae are still acceptable, with the exception of CMC(I:c) formula. The performance of staining assessment was also examined as well, using CIELAB, SSR(UK), SSR(ISO), Ns and Fs. The result shows that all of them possess good relationship with the visual assessment, with the correlation coefficient values higher than 0.960.