Effect of sample size on colour fastness assessment

In the present paper the effect of sample size on the colour fastness assessment was investigated. To do so, 28 simulated colour fastness panels for colour change assessment were prepared by available dyed cotton fabrics. Then, by locating a mid-gray frame on the panels, four visual fields of 1o, 2o, 4o and 10o were obtained and the colour fastness of the panels was assessed visually and the corresponding assessments were compared. Also, by the application of an existing colour size model and the GRC instrumental colour fastness formula, the fastness of each panel was calculated and compared with the corresponding visually assessed one. The results showed that, the larger is the size of the sample, the lower colour fastness is given to the same panel, however, it was concluded that the size effect on colour fastness assessment is not practically significant.