Intaglio
A printing technique from a plate, where printing elements are incised into the surface. Spacing elements are above the printing ones. A viscous ink fills in the recessed areas of the printing plate and is transferred to the substrate under high pressure (80–100 kg/cm2). The pressure forces the substrate into the recessed areas.
Characteristic features of the prints:
- A thick ink layer which produces relief;
- A wide range of tone transfers due to different depth and width of strokes;
- Substrate deformation (inward bulging from reverse side);
- Ink creeping between paper fibers at strokes edges (fig. 1).
Polymer banknotes may not have ink creeping.
a
b
Fig. 25. Zoomed area of the image printed by intaglio. 500 Hong Kong Dollars (1997):
a – front side, showing a wide range of tone transfers and ink creeping at strokes edges; b – reverse side, showing paper deformation (inward bulging) at the printed area