thumb|2005 self-adhesive stamp of [[Deutsche Post. (450 years after "Augsburger Religionsfrieden")]]
A self-adhesive stamp is a postage stamp with a pressure-sensitive adhesive that does not require moistening in order to adhere to paper. They are usually issued on a removable backing paper.
Stamp collectors have criticized the format, because the rubber-based adhesive used tends to yellow the stamps progressively. It makes stamps difficult to remove from covers, however various household solvents can be used to separate used self-adhesive stamps from their envelopes. and Sierra Leone in February 1964 in an attempt to avoid the tendency of traditional water-activated stamps to stick together in humid conditions. They also made die cutting into fanciful and unique shapes easier.
In the UK
The Royal Mail first issued self-adhesive stamps on 19 October 1993, with the introduction of booklets of 20 first class Machin stamps printed by Walsall Security Printers by offset lithography; later a second class stamp was introduced. In the years following, other issues were produced in the self-adhesive format.
Die-cutting tools for the UK self-adhesive stamps were manufactured by Arden Dies of Stockport, Cheshire, using tools designed by Robert Clapham.
In the US
thumb|The first U.S. self-adhesive stamp
The United States Postal Service's first foray into self-adhesive stamps was in 1974 with the 10-cent dove weathervane, that soon became discolored due to the instability of the adhesive. However, Avery Dennison continued adhesive technology research with pioneering work by M. Shams Tabrez, a chemist. It was in 1989 that another such self adhesive stamp was issued by the USPS.
See also
- Pressure-sensitive adhesive