Patent ID: 11890888
Assignee: THE GOVERNMENT OF THE UNITED STATES OF AMERICA, REPRESENTED BY THE SECRETARY OF HOMELAND SECURITY
Field: Textile and paper machines (Mechanical engineering)
Classification: CPC B | IPC B

Claim 16:
17. A method of printing anti-counterfeit markings on a substrate having front side markings on a front side and back side markings on a back side, the method comprising:
printing with an offset printing press configured to print with a first printing plate to print on the front side of the substrate:
a first printed substrate marking printed with a first ink color at a first saturation; and
a first printed substrate symbol printed with the first ink color at the first saturation;

printing with the offset printing press configured to print with a second printing plate to print on the back side of the substrate:
a second printed substrate marking printed with a second ink color at a second saturation, the first ink color and the second ink color having a same hue, the first saturation being different from the second saturation; and
a second printed substrate symbol printed with the second ink color at the second saturation; and

printing with the offset printing press configured to print with a third printing plate to print on the back side of the substrate:
a third printed substrate marking printed with the first ink color at the first saturation; and
a third printed substrate symbol printed with the first ink color at the first saturation;

the first printed substrate marking, the second printed substrate marking, the third printed substrate marking, the first printed substrate symbol, the second printed substrate symbol, and the third printed substrate symbol being printed to provide:
a pattern of low saturation and high saturation printed substrate markings visible in the first ink color when the substrate is viewed with transmitted light;
the second printed substrate symbol visible in the second ink color in the second saturation when the substrate is viewed with transmitted light;

the first printed substrate symbol being formed by printing the front side of the substrate using a first printing plate symbol on the first printing plate;
the third printed substrate symbol being formed by printing the back side of the substrate using a third printing plate symbol on the third printing plate; and
the first printing plate symbol of the first printing plate and the third printing plate symbol of the third printing plate, when the first printing plate and the third printing plate are aligned for printing on the front side and the back side of the substrate, respectively, covering an overlapping space in which the first printing plate symbol and the third printing plate symbol are not spatially distinguishable.