| abstract |
A planographic printing method using ink selected from yellow, rouge, indigo and Indian inks, characterized by printing yellow, rouge, indigo and Indian inks with the density values of yellow, rouge, and indigo inks as density values 1.0-1.5 times the reference density values by using yellow, rouge, indigo and Indian inks where a representable color number when yellow, rouge, indigo and Indian inks are printed with the density values of yellow, rouge, and indigo inks as reference density values is at least 1.1 times the representable color number when yellow, rouge, indigo and Indian Japan color standard inks are printed with the density values of yellow, rouge, and indigo Japan color standard inks as reference density values. In the above, reference density values are 1.40-1.44 for yellow, 1.52-1.56 for rouge and 1.63-1.67 for indigo, and a representable color number is a color that can be represented when yellow, rouge, indigo and Indian inks or yellow, rouge, indigo and Indian Japan color standard inks are printed, and is the number of colors that can be represented by an L*a*b*color system (L*=10y(y, an integer of 0 to 10), a*=10x(x, an integer of -12 to 12), b*=10z(z, an integer of -12 to 12)). |