Abstract
When image information is conveyed with paper media, the information is greatly altered by the paper properties. Printing-related properties of paper and their definition and testing methods were described with reference to JIS specifying the testing methods. Paper is hygroscopic and the standard atmosphere for testing paper is specified to be 23°C and 50% relative humidity. Basis weight, thickness and density were described as structural parameters. Illuminant C diffuse illumination/normal view is the standard optical condition, and details of brightness, opacity, color and gloss were explained. High opacity peculiar to paper is ascribed to its high specific light scattering coefficient. Then, its calculation method and difference between paper and plastic sheets were demonstrated. For mechanical properties, tensile strength, folding endurance, tear strength and paper-to-paper friction were described. Finally, it was reported as a recent trend of ISO standard that new testing standards about recycled pulp and paper are being established.
