Colour fastness to washing of multi-layered digital prints on textile materials

This paper considers the influence of multiple ink jet printed layers and woven fabric thread count on the colour fastness to washing of printed polyester textile products. The goal was to investigate the possibility for optimisation of the number of ink layers and thread count in order to increase print quality and colour fastness to washing. Materials with the same composition and different thread counts were printed ranging from one to five ink layers. The samples were subjected to washing process after which colour fastness was examined according to appropriate standards. The colour fastness was judged subjectively by trained professionals using the standard grey scale, and objectively using spectrophotometric measurements, with calculation of colour differences caused by the washing. Surface changes were observed using SEM analysis. Results indicate that multiple layer printing gives more saturated colour due to better ink coverage, but on the other hand it enhances the ink wash-out effect. The research suggests the possibility of optimising the number of ink layers in relation to thread count number when print quality and colour fastness to washing is the objective.