Nils Pauler, Ole Norberg, Per Edström
It is known that colour reproduction of inkjet comprises a range of mechanisms. It was possible to understand and explain some of these mechanisms by evaluating print tests with standard optical measurement and by calculations using algorithms of the Kubelka Munk and Murray Davies theories. The combined interaction of the substrate, the ink penetration, the optical properties of the inks and the dot size were clarified. Large colour gamut is governed by low ink penetration, low light scattering of the substrate and small dot size. The non-ideal property of process inks and the continuous tone character of colour reproduction of the studied desktop inkjets explained the observed convex shape of the colour gamut. For plain paper, dye-based and pigment-based inks were shown to follow different mechanisms, with lower penetration of the pigment-based ink. Colour gamut could be increased by a surface treatment that further reduced the penetration, but this treatment worked only for the pigment-based inks. Internal sizing of plain paper had only a very small influence on colour gamut for dye-based ink, even though the ink penetration was reduced.
Keywords: Paper, Inkjet, Colour Gamut, Simulation, Kubelka Munk, Murray Davies