How can I tell the difference between self-adhesive and gummed stamps?
The different perforations used for self-adhesive (peel-and-stick) and gummed stamps will allow you to identify the style of stamp. Perforations are used to allow stamps to be easily detached from each other. Gummed stamps are perforated by cutting rows and columns of small holes. These are of identical size on all four edges of each stamp. Self-adhesive stamps are cut to shape by using a metal die. Dies can be produced to cut stamps in virtually any shape, i.e., self-adhesive stamps currently have a flat section at their top and bottom.
