Shadow Image
A tonal image seen in transmitted light; produced by altering the opacity or the colour of a polymer substrate layer. The element is similar to a watermark in the cotton-paper banknote.
Classification
Depends on the location on a banknote:
- Local is a shadow image located in a particular area of a banknote (fig. 1, a);
- Strip is shadow images located one above another in a particular area of a banknote (fig. 1, b).
a
b
Fig. 1. Shadow image. Transmitted light:
a – local. 20 New Israeli Sheqalim (2008);
b – strip. 20 Honduras Lempiras (2008)
Depends on the tone gradation:
- Single-tone – consists of darker (or lighter) elements compared to the general tone (fig. 2, a);
- Duotone – consist of darker and lighter elements (fig. 2, b);
- Multi-tone (half-atone) – an image with gradual transitions between darker and lighter areas (fig. 2, c).
a
b
c
Fig. 2. Tone gradation of the shadow images:
a – single tone. 5 Brunei Dollars (2002); b – duotone. 20 Honduras Lempiras (2008); c – multi-tone. 20 New Israeli Sheqalim (2008)