PRINTING. The ageing resistance of offset and electrophotographic prints

Abstract

Abstract The moist heat (80°C and 65% relative humidity) and light (xenon arc lamp) treatments of accelerated ageing were applied to investigate the colour stability of offset and electrophotographic prints on papers made of virgin and I 00% recycled fibres. The prints were evaluated using spectrophotometric measurements and additional colour differences calculations. In addition to the colour differences, the 2D and 3D colour gamuts are presented. The results reveal the different colour stability of prints. The effect depends on the type of accelerated ageing, printing technique, composition of ink and paper characteristics. Moist heat ageing has less influence on colour stability than light ageing. The electrophotographic prints show better ageing resistance than offset prints. The intluence of ink on print light fastness is considerable. Azo pigments in magenta and yellow have lower light fastness than phthalocyanine pigments in cyan or carbon black. The surface coating has an intluence on light fastness of prints. Meanwhile, prints on recycled papers show similar colour stability compared to prints on papers made of virgin fibres