Stamp / Seal
A seal, an impression, a mark or relief formed as a result of pressing a special tool (stamp) to a paper substrate.
Types of stamps differ according to the application method:
- ink stamps — flat impressions on the substrate;
- dry stamps — impressions in relief, no ink is used.
A dry stamp is viewed under oblique light and perceived by touch. Substrate deformation is observed both on the front and back of the stamp. The embossed elements on the front are absolutely similar to the depressed elements on the back.
a
b
c
Fig. 1. Azerbaijan. Passport issued in 2007:
a — page spread (pages 2-3). Paper substrate; b — the same. Ink stamp; c — the same. Zoomed fragment. No relief
a
b
c
Fig. 2. Viet Nam. Passport issued in 1993:
a — page spread (pages 2-3). The holder's portrait is glued and stamped; b — the same. Dry stamp; c — the same. Zoomed fragment. The surface relief is visible in oblique light