Abstract: To prepare a decorated printed matter, which excels in the visibility of the spin line or hairline pattern and which gives an appropriate metallic luster. A decorated printed matter which comprises: a plastic plate 1 with a light permeability, the plastic plate 1 is made of poly carbonate and is provided a convexo-concave pattern consists of a plurality of fine grooves 2 in the form of spin line on a rear-side surface 1b thereof; an ink coating 3 covering the convexo-concave pattern; and the ink coating 3 is formed by removing a solvent from an ink composition coated on the rear-side surface 1b of the plastic plate, the ink composition includes a carbon black and a binder; the average ratio of carbon black to binder is determined such that the distribution of the black pigment in the ink coating becomes the distribution by which an incident light incoming into the resin substrate from the front-side surface thereof reflects at an interface between the resin substrate and the ink coating.

Abstract: A gradation pattern is formed by sandblasting a surface of a transparent substrate. The gradation pattern comprises countless recesses formed by eroding the surface structure. The distribution density of the recesses is low in the vicinity of sides on which primary illuminating light is incident, and high in the center of the pattern. As the original flat and smooth aspect of the plate is maintained between the recesses, the light guiding performance of the plate is maintained. By adjusting the gradation pattern, any desired bright/dark pattern can be obtained. The cost of manufacturing a light guiding plate and flat optical source device is reduced. A large illumination area having a high uniform brightness is made possible by sandblasting. And many applications and modes of use which were impossible with a conventional light guiding plate having a printed pattern, are now possible.