PURPOSE: To reduce cost to a large extent by almost reducing the wt. and thickness of a book or printed matter to half by using inks of two colors to one printing paper to print characters or pictures of separate contents in combination and matching two transparent overlays of two colors with the printing paper to look the book or printed matter.

CONSTITUTION: Types 4, 5 of separate contents are printed on one printing paper 1 by inks of two colors A, B and, when a book is looked, two transparent overlays 2, 3 of two colors A, B are used and, when the type 4 of the color B is looked, the transparent overlay of the color A is used and, when the type 5 of the color A is looked, the transparent overlay of the color B is used to look the book or printed matter. The inks are desirably set to a white/blue type color and a white/red type color and a synthetic color to be looked is desirably black. The transparent overlays 2, 3 of two colors A, B are set to a white/blue type and a white/red type and the colors of the inks and those of the transparent overlays are combined so that types 2, 3 or pictures to be looked are clearly looked and types 2, 3 or pictures not looked disappear perfectly and the densities of the transparent overlays are controlled.