Mint vs. used stamps

The labels, from best to worst

Dealers and auction houses describe the back of a stamp as carefully as the front. These are the terms you will see:

Why never-hinged stamps cost more

Undisturbed gum is proof that nothing has been done to the back of the stamp. Mystic Stamp Company notes that terms like MNH signal how much of the original adhesive remains, which "makes them more desirable and often drives significant premiums."

The premium has a defensive origin. Peter A. Robertson of the Philatelic Foundation traces it to buyers who "were trying to protect themselves from buying damaged or repaired stamps." Regumming is the reason: Robertson writes that "stamps almost always are regummed to hide defects," and that the practice has been around since the 1860s or early 1870s.

For ordinary material the gap is real but modest. The American Philatelic Society says that "in the vast majority of cases unused stamps sell for more" than used ones, but it also notes that most US stamps issued since 1940 sell at or around face value, mint or not.

Old stamps play by different rules

Early collectors didn't care much about gum. Mystic writes that "in the early days of philately, gum was not seen as particularly important," so countless older stamps lost it long ago. The grading conventions reflect that:

• Stamps from before 1890 can be described as mint without gum, whether or not they were issued with it.
• Stamps from before 1940 can show hinge marks and still be considered mint.
• Stamps from 1940 to the present are generally expected to be never hinged, so a hinge mark on a modern stamp counts against it.

In practice: a hinged 1950s stamp is a lesser copy, while a no-gum 1870s stamp is normal. Don't soak an old mint stamp to "clean" it; the water removes whatever gum is left.

How to spot a cancelled-to-order stamp

Some postal administrations cancelled sheets of stamps and sold them to the stamp trade, often below face value. These cancelled-to-order (CTO) stamps never carried mail. Wikipedia names the emirates that later joined the United Arab Emirates among the issuers.

They are easy to recognize: the cancellation is neat, usually in one corner, often without a town name, and the gum is still on the back. A real postally used stamp almost never keeps its gum. An apparently used stamp with full gum may be CTO and have little or no value to collectors.

How to check your own stamps

• Turn it over under a lamp and tilt it. Undisturbed gum has an even sheen; a hinge leaves a dull rectangle or a paper remnant.
• Date it first. The same hinge mark matters far more on a 1960s stamp than on an 1880s one.
• Be suspicious of perfect gum on a very old stamp. It may be regummed, which buyers treat as damage.
• Store mint stamps in mounts, not hinges, if you want to keep them never hinged. See stamp hinges and mounts.
• Grade the front too. Centering and faults count as much as gum; try the centering grader.