If you have stamps at home that you have kept for sentimental reasons or on the off-chance that they are rare and valuable, you could find out at an exhibition this weekend what they are really worth.
Free valuations on individual stamps or whole collections are being offered at Stampa 98, the Irish National Stamp Exhibition, which begins this morning at the RDS in Dublin. Mr Michael Kelly, one of the council of organisers of the An Post-sponsored exhibition, debunks a myth about the penny black: "Some people believe the penny black is a very valuable stamp. But it's not necessarily. There were millions of them printed."
But the penny black had a built-in code. In each corner a tiny, barely visible letter was printed to prevent forgery. Each printer's plate had different letters, such as AA in the top two corners and BB in the bottom corners. Certain penny blacks are valuable if there were very few stamps of a particular code issued, he says.
You can buy a penny black - the first adhesive prepaid postage stamp - for as little as 20p or £10 or £12 at the Stampa exhibition. Others are valued at £400 or £500, he says. But you can also see the world's earliest recorded penny black at the RDS which is estimated to be worth more than £200,000.
The date of issue of the penny black was May 6th, 1840. But the highly-valued exhibit at Stampa is on a cover or envelope dated May 1st, 1840. The cover shows that the recipient incurred a 2d charge - 1d postage plus 1d fine, because the stamp was not valid until five days later.
Another valuable exhibit at Stampa 98 is a set of four 2d coil perforated Irish stamps in mint condition issued in 1934. This strip of four was purchased from a post office stamp dispenser machine. But unlike today's machines which dispense booklets of stamps, these philatelic rarities were on a single perforated roll, from which you tore off the stamps having paid the money.
"These coil stamps are very rare. They were used for something like eight or 10 years but only so many rolls were made so they are scarcer than the normal stamp. Their survival rate was a lot less as well," he says.
These four stamps are unique because they remain in the vertical strip, are in mint condition and the only surviving other multiples are in pairs.
Moreover, fewer than 25 unused examples are recorded. That small strip of four is estimated at £50,000. Other valuable stamps to look out for include standard English stamps overprinted with Rialtas Sealadac na hEireann 1922 or Saorstat Eireann at Eireann.
"After May 1921 only English stamps overprinted with the Irish Provisional Government could be used," he says. Particularly valuable are the two and six, five shillings and 10 shillings overprinted stamps. An unused mint set of three could be worth £2,200 for the dearest set, or £240 for the cheapest set (depending on which printer was used). Meanwhile, any of these individual stamps should fetch £50 or £60 in good condition.
Generally, higher denomination stamps - whether mint, unused or used - can be indicators of value. For instance, a shilling, two and six, five shilling or 10 shilling stamp would tend to be more valuable than a penny, two pence or three penny stamp, he says.
Age is another criterion of possible value. Modern stamps are brightly coloured, while "old stamps tend to be line-engraved drawings in monochrome", Mr Kelly says.
Stampa 98, the Irish National Stamp Exhibition, opens this morning at the RDS, Ballsbridge, Dublin. Times: 11 a.m. to 6 p.m., Friday to Sunday, inclusive. Prices: adults, £4; children, £2; school groups, £1 per child.
