Watermark
An image visible in transmitted light only, incorporated into the paper during its manufacturing process. A watermark has slightly diffused blurred contours and gradual transitions of the tones. It is formed by the density of the fibres on certain areas of the image. Thus, darker elements of the watermark are located on more dense areas of the paper, and lighter elements are located on less dense areas. The watermark does not appear under UV light.
Classification
Location:
- General watermark is an image repeated all over the banknote (fig. 1);
- Local watermark is an image located in a specific place of the banknote (fig. 2);
Fig. 1. General.
500 Cambodian Riel (1996)
Fig. 2. Local.
1 000 Belarusian Rubles (2000). Modification 2011
- Strip watermark is a band of images repeated one above another; is located in a specific place of the banknote (fig. 3);
- Cornerstone watermark consists of several parallel diagonal lines located in the banknote corners (designed to physically strengthen the corners (and edges) of banknotes) (fig. 4).
Fig. 3. Strip watermark.
100 Norwegian Kroner VII series (1995–2002)
Fig. 4. Cornerstone watermark.
1 Libyan Dinar (2009)
General paper tone:
- Single tone watermark consists of darker (or lighter) elements compared to the general paper tone (fig. 5);
- Duotone watermark consist of darker and lighter elements compared to the general paper tone (fig. 6);
- Halftone watermark is an image with gradual transitions between darker and lighter areas (fig. 7);
Fig. 5. Single tone.
10 Belarusian Rubles (2000)
Fig. 6. Duotone.
500 Cambodian Riel (2004)
Fig. 7. Halftone.
20 Belarusian Rubles (2000)
- Pixel watermark is formed by dark dots on the light background (fig. 8);
- Highlight watermark (electrotype) is an extremely light clear single tone watermark with clear boundaries (fig. 9);
- Combined watermark combines several kinds of watermarks (fig. 10);
- Coded watermark consists of dark and light vertical strips located on the printed area of the banknote (is used as a machine-readable feature) (fig. 11).
Fig. 8. Pixel.
1 000 Kazakh Tenge (2011)
Fig. 9. Highlight.
1 000 Czech Korun (2008)
Fig. 10. Combined (halftone and highlight).
50 Gibraltar Pounds (2010)
Fig. 11. Coded.
500 Euro (2002)