Watermarks are created by producing variations in the thickness of the paper, and can be either light or shaded. They are combined to pattern banknotes elaborately.
Watermarks also include tactile marks to help the visually impaired people distinguish different denominations.
Image designs of the values and portraits on banknotes are thickly printed to give a notable texture.
Banknote designs are drawn with extremely fine lines. Such fine lines can hardly be replicated by color copy machines, or by ordinary printing equipment or similar devices.
Banknotes with serial numbers in brown or dark green have a seal on the front side that glows under ultraviolet light.
Banknotes with serial numbers in brown or dark green have the words “NIPPON GINKO” printed in small characters that can hardly be reproduced by color copy machines or similar devices.