Collecting: Putting it philately, the price of old stamps is travelling

In for a Penny Black, in for thousands of pounds - why knowledgeable investors are licking their lips

One of the most impressive stamp collections in the country is expected to fetch as much as £11m when it is auctioned at Sotheby's next month.

The collection, owned by the late Sir Gawaine Baillie, specialises in Britain and the British Empire. It includes some highly sought-after items, such as a block of four 1840 2d blue plate stamps, estimated at £45,000 to £50,000, and the 1880s 2s brown in a unique pane of 20, estimated at £200,000 to £250,000.

This sale, which includes items not seen by the public for around half a century, provides yet another example of the astonishing rise in value of stamps in recent years. Stanley Gibbons, which sells and buys stamps and is the authority on the subject both in this country and abroad, reported impressive profits earlier this year and Richard Purkis, its operations director, is bullish about the financial performance of stamps: "It has proved an excellent investment over the past few years. Current trading is ahead of the same period last year in turnover and profitability."

He points to the company's own stamp price index, which shows a 33 per cent increase in less than five years. The index contains price histories of 30 of the rarest British stamps.

One of the top performers is the mint 1882 £1 Anchor watermark on blued paper, which has risen in value from £32,000 in 1999 to £65,000 in 2004.

"The market is underwritten by the large and growing number of collectors," says Mr. Purkis. He makes particular reference to the emerging Indian and Chinese markets, where more people with disposable incomes are joining the party.

There are now 30 million stamp collectors worldwide, and their enthusiasm has helped push up the value of stamps as an alternative investment by 10 per cent per annum between 1907 and 1990, according to a Salomon Brothers survey. Individual stamps can be worth tens of thousands of pounds, depending on certain factors, although there are many fakes and cheap replacements that can catch out the unwary.

For example, the first adhesive stamp, the Penny Black, was originally issued on 6 May 1840. If, on searching your attic, you happen across one in mint condition from the corner of the sheet and carrying the plate number, it could be worth £30,000. But don't celebrate yet as even genuine Penny Blacks can be worth as little as 50p.

Product knowledge is the key. "You have to know more than the person you are buying from," says Miller McGrath, whose specialist area is Polish stamps. Mr McGrath, like many keen philatelists, is also interested in other areas of postal history, specifically the history and development of the Scottish postal system. "The bulk of my interest is the pre-1840 period, not just stamps - how an item got from 'a' to 'b' and why it took a particular route."

The need for in-depth knowledge is demonstrated by one attractive item from 1926, when the Postal Union Congress GB issued a £1 stamp bearing a picture of St George and the Dragon. In 1970 the market price for this was £70. By 1980 aggressive dealers had spotted an opportunity and pushed it to the region of £1,300. However, the bubble burst on this line and the true market value established itself at £450 soon after.

Talking to collectors reveals what drives them. They are interested in postmarks, the history of letters and the routes taken by them, as well as the politics, the geography and the printing process that lie behind a stamp. The stamp itself is the emblem of the whole story and, in the case of a true philatelist, represents only a fraction of their understanding.

Philatelist Colin Mount echoes this sentiment: "Over the years I have developed a deep knowledge of the Australian George V Penny Red that means I often know more than the dealers about the subject."

As with most forms of collecting, enthusiasts tend to be male, but there are some notable female collectors. Jane Moubray is a signatory of the Royal Philatelic Society's Roll of Honour - the highest of philatelic accolades.

"The profile is changing and more women are being attracted to philately," says Ms Moubray, who demonstrates admirable pragmatism in her area of specialisation. "I chose the 1841 2d blue because it gave me everything I was looking for but was less sought-after and therefore less expensive than the Penny Black," she adds.

As an international judge, she is also well placed to offer a simple tip to the newcomer: join a society. "Not only does this provide a pool of knowledge, it affords opportunities to see many and varied collections in a sociable environment."

So what should the new collector look for? "Quality and condition is of utmost importance," says Mr Purkis. Rarity is also important but the ability to identify this requires a big investment of time and effort.

Adrian Roose, who works in Stanley Gibbons' investment department, summarises the basic tenet of investment: "Purchase material of the highest quality, as the finer-quality items continue to outperform material of lower grades."

Stanley Gibbons reports an increase of 5,000 new customers per annum for the past three years, which, it argues, helps underpin the value of stamps.

Nevertheless, the key seems to be to invest in good-quality items that you find intrinsically interesting. This way, you have a better than reasonable chance of developing a collection that will reward you with enjoyment as well as a profit.

FIRST CLASS

Prices: from a few pence to several hundred thousand pounds.

More information: Royal Philatelic Society, www.rpsl.org.uk or 020 7486 1044;

Stanley Gibbons, www.stanleygibbons.com or 020 7836 8444;

The British Library philatelic collection, http://portico.bl.uk/collections/philatelic;

For local societies, see http://ukphilately.org.uk

Events: the Sir Gawaine Baillie collection is on sale at Sotheby's, New Bond Street, London from 29 September to 1 October