Self-adhesive stamp

It makes stamps difficult to remove from covers,[1] and to save in mint condition, though self-adhesives of recent years have improved in these respects.

[citation needed] They were first issued by governments in tropical climates such as Sierra Leone in February 1964[2] and Tonga in April 1969 in an attempt to avoid the tendency of traditional water-activated stamps to stick together in humid conditions.

[citation needed] The United States Postal Service's first foray into self-adhesive stamps was in 1974 with the 10-cent dove weathervane,[2] produced by Avery Dennison,[5] that soon became discolored due to the instability of the adhesive.

[1] More recent USPS self-adhesive stamps are not readily removable from the envelope or cover backing by traditional water soaking.

Some collectors of used stamps have discovered that although not readily removable by water, the self-adhesives can be removed with Bestine (a heptane solvent), benzine (petroleum ether), or a natural based citrus solvent containing d-limonene (e.g., Pure Citrus Orange is an air freshener product that works for this purpose).