Unhinged - a stamp without hinge marks, but not necessarily with original gum.
Unitrade Specialized Catalogue of Canadian Stamps - specialized stamp catalogue published by Unitrade Associates on an annual basis.
Unhinged: A stamp without hinge marks, but not necessarily with original gum.
Universal Postal Union: An international organization formed in Bern, Switzerland, in 1874, to regulate and standardize postal usage and to facilitate the movement of mail between member nations.
Unhinged - A stamp without hinge marks.
Unissued - Stamp prepared for postal use but which are not issued.
Universal Postal Union (UPU) - An international organization which regulates postal usage and aides in moving mail among its member nations.
- Unhinged, a regummed stamp that has not been affixed to a hinge or a stamp mount.
- No gum or Ungummed, a stamp that has no adhesive on its back. It may have been intentionally produced with adhesive or the adhesive was removed by soaking.
Since the time that unhinged stamps became popular, considerable numbers of old stamps with intact gum have appeared on the market, raising suspicion that many of these have been regummed.
 References ...
Hinging mint stamps causes them to lose some of the original gum, thereby causing them to be worth less than they would be if they were unhinged.
Stamp Mounts - These are considerably more expensive than hinges. They are usually made out of plastic.
stamps around with perfect unhinged backs than ever it is because there are. While for us the collecting of postage stamps is a pleasurable pastime, for others it is a money making opportunity.
He hadn't thought of an unhinged sheet and typewriter. Another collector-of the true amateur type-had duplicates and triplicates of valuable stamps mounted one under the other in a printed album.
See also: What is the meaning of Stamp, Used, Hinged, Hinge, Mint?