High Speed Ink Liquid Interface Dynamics in Ultra Light Coated Virgin Hardwood Graphic Papers
Ultra-light coated virgin hardwood papers demand sub-50nm coat pore radii to balance high-speed inkjet solvent absorption against hardwood fiber swelling.
Optical Strike Through
Opacity Assessment
Visual assessments determine the visibility of a printed image on the reverse side of a sheet due to the transparency of the substrate. Optical strike through occurs when light passes through the paper and reveals the ink on the opposite side without any physical movement of the pigment through the fibers. It is measured as the ratio of the reflectance of the printed area to the reflectance of the unprinted reverse side.
Sheet Density
The thickness and filler content of the paper are the primary factors that prevent light from revealing the image. Thin papers with low grammage are more prone to this effect. High levels of titanium dioxide or other opaque fillers can reduce the visibility of the reverse image by increasing light scattering within the sheet structure.
Print Contrast
High contrast between the ink and the paper increases the likelihood of the image showing through. When using dark inks on light, lightweight stocks, the effect becomes more pronounced and can interfere with the readability of text on the following page. Selecting a grade with higher scattering coefficients or adding a pigmented coating helps maintain the integrity of the design.
This property is a major constraint in the design of thin publications and catalogs. It dictates the maximum ink coverage allowed for specific paper weights in the newspaper and magazine sectors.