Paper surface efficiency and inkjet colour reproduction on invasive and agro residue papers

Abstract

Paper surface efficiency was developed by Preucil and was intended to define the colourimetry and geometrical part of the light reflection with paper surface values. The surface characteristics of paper, primarily its roughness and absorptivity affect colour reproduction beside the ink pigments or dye. Rougher paper surfaces scatter the light in a more non-uniform manner while paper absorption may cause ink vehicle absorption and thus decreasing gloss, or it may absorb both vehicles and pigment-producing an unexpected colour shift. The formula was upgraded with paper whiteness values as the basic formula did not explain the whole phenomena. These paper properties were the foundation of the paper standardisation for standardised printing. On the other hand, during inkjet printing, a limited amount of liquid is deposited onto a paper surface. When the droplet hits the surface, it starts to spread and wet the surface depending on the ink and paper properties and had different colourant deposition from the formulas used mainly for offset printing inks. In this paper, we have researched the modified surface efficiency formula applied to inkjet printing (HP PageWide Pro 477dw) on invasive and agro-residue papers with specific non-white paper shades. We have measured the dynamic liquid penetration using ultrasound measurement to model the surface behaviour of the inks and measured CIE LCH values of the samples and calculated the CIE ΔE00 colour differences and the influence of paper surface efficiency and paper shade influence on the colour reproduction. The results indicate that using recalculated Cobb Absorption values gives good negative linear correlation with the original formula regarding the magnitude of colour difference.