Identifying rare and valuable postage stamps
Inverted centres, imperforate pairs, colour errors — the key varieties that separate a treasure from a common stamp.
What makes a stamp genuinely rare
Genuine rarity in stamps comes from one of three sources: low original printings, high attrition over time, or being an error that almost never entered circulation. Classic stamps from the mid-19th century — the first period of widespread stamp use — were produced in quantities that seemed large at the time but have dwindled over 170 years of postal use, loss, and destruction. An 1847 US 5-cent Benjamin Franklin stamp survives in only a few thousand examples from an original printing of around 3.7 million; condition loss has made superb copies genuinely scarce. Errors and varieties, when they arise, are usually caught before distribution — only a handful escape to collectors. Error stamps that reached the public in significant quantities (over 100 examples) are far less rare than those represented by a single block or strip. High attrition affects certain types — stamps used on overseas mail were often damaged by humidity and rough handling; fiscal use could damage or discolour; and many early collections were broken up and scattered.
Major classical issues worth knowing
Several stamp issues have achieved legendary status in philately. The 1855 Swedish Treskilling Yellow — an error stamp printed in orange-yellow rather than its correct blue-green — has sold for record sums because it is the only known example. The 1855 British Guiana 1-cent magenta is another unique piece, the world's most famous single stamp. The US 1869 inverted centre series produced several invert varieties across different denominations, with survival numbers ranging from about 100 to fewer than a dozen. Britain's 1840 Penny Black and Twopenny Blue are not rare by survival numbers but hold great historical significance as the world's first adhesive postage stamps. For collectors at more accessible price points, the 1930s–1960s era of many Commonwealth countries offers stamps that are scarce in superb mint condition but attainable: New Zealand health stamp se-tenants, Australian pre-decimal high values, and Canadian King George VI high-value definitives all have genuinely collectable high-grade examples.
Philatelic certificates and why they matter for rare stamps
For stamps at the upper end of the value scale, philatelic certificates from recognised expertising bodies are close to mandatory for serious transactions. A certificate provides three assurances: the stamp is genuine (not a forgery or a fake cancel on a mint copy); the variety identified is correct (the right perforation gauge, watermark type, and shade); and the condition is accurately described (no thins, no repairs, no regumming). Forgeries of classic rare stamps have been produced since the 19th century, some of extremely high quality that fool casual observers easily. Expertising bodies maintain reference collections and have experienced examiners who can distinguish genuine examples from even sophisticated fakes. For any stamp purchase at a significant price where no certificate already exists, budget for obtaining one from the appropriate national body before making the investment.
FAQ
How can I tell if a stamp has been regummed?
Regumming — applying new adhesive to a stamp that originally had no gum or damaged gum — is one of the most common forms of philatelic fraud for classic mint stamps. Detection methods include examining the gum under magnification for brush strokes or unnatural uniformity, checking whether the gum matches the period's known gum types (pre-1935 US gum was typically yellowish and crinkled; post-war gum is brighter and smoother), and looking for gum 'skips' at the perforations where applied gum doesn't flow into the teeth the same way as original. Expert certificates address this specifically. Do not use watermark fluid on suspect stamps before examination — it can disturb surface gum evidence.
Are topical or thematic stamps a good collecting strategy?
Topical collecting — assembling stamps by subject matter (trains, birds, butterflies, space exploration, maps) regardless of country — is one of the most popular approaches to philately precisely because it makes the hobby accessible and thematically satisfying without requiring deep expertise in a single national series. Topical collections often have lower entry costs since many thematic stamps are common modern issues. The challenge is that topical stamps generally resell less efficiently than classic series stamps, because the buyer pool is more diffuse. Many experienced collectors combine topics with a focused national or period specialty for the best of both approaches.
What does 'OG' or 'NH' mean on a stamp description?
OG stands for Original Gum — meaning the stamp retains the adhesive applied at the time of printing, as opposed to a regummed or no-gum example. NH means Never Hinged, indicating the original gum has never been disturbed by a mount hinge. LH (Lightly Hinged) means a hinge was applied but left only a minor remnant. H or HR (Hinge Remnant) means a more substantial trace of the hinge remains. OG-NH stamps command the highest prices for classic mint issues; OG-LH trades at a moderate discount; and OG-H at a larger discount. No-gum (NG) stamps are typically sold as space fillers or for their used equivalents unless the design is only collected without gum.