1. A measuring tool, comprising: a transparent sheet; a first pattern of markings on the transparent sheet for measuring characteristics of a test sheet, the first pattern of markings including: a first scale for measuring distances in a first direction to one edge of the test sheet; a second scale for measuring distances in a second direction perpendicular to the first direction to another edge of the test sheet; a square for measuring perpendicularity of two intersecting edges of the test sheet; and a third scale for measuring the magnitude of a deviation in perpendicularity of the intersecting edges of the test sheet with respect to the square; and a second pattern of markings on the transparent sheet for measuring characteristics of a target image printed on the test sheet, the second pattern of markings including: a fourth scale for measuring a distance in a first direction to one side of the target image; and a fifth scale for measuring a distance in a second direction perpendicular to the first direction to another side of the target image.