1. A printing relief plate having convexities formed on a surface of a plate material, the convexities being adapted to print halftone dots on a print medium by transferring ink to the print medium, on the surface of the plate material, the printing relief plate comprising: a solid area; an image forming region in which the convexities are formed in plurality; and at least one detecting portion is used for determining a magnitude of a printing pressure applied to the printing relief plate in a case where ink is transferred to the print medium from the printing relief plate; the convexities and the detecting portion are positioned lower than the solid area; and the at least one detecting portion is used for determining whether the printing pressure is an appropriate printing pressure by comparing a density of at least one detecting portion image, which is printed on the print medium by transferring ink to the print medium from the detecting portion, with a density of a solid area image, which is printed on the print medium by transferring ink to the print medium from the solid area, wherein the detecting portion is a recess formed in the solid area, and wherein a height position of a bottom surface of the recess is substantially the same as a height position of an apex of a lowest highlight convexity.