INSTRUMENTAL SHADE SORTING IN THE PAST 3 DECADES

Colourists often need to manufacture a production batch of a large num ber of rolls of fabric to match a colour provided by a client. However , even fabrics dyed with the same colorants under well monitored condi tions may show some colour variation. This variation should be charact erised and the fabrics separated into groups within which the colour d ifference is considered acceptable. A systematic shade sorting process enables colourists to do this before delivery. We review the criteria for implementing such a system, along with the merits and demerits of the fixed grid and the grid-free system. Methods for separating the c oloured sample population and determining the tolerance limit for acce ptable shade groups are also outlined. Such studies should be carried out continuously so that a comprehensive and well organised shade sort ing system can be developed.