Nowadays every postal administration churns out commemorative and special issues at frequent intervals, while many also release charity or semi-postal stamps from time to time. These stamps certainly add colour and excitement to our mail, but there are also those stamps which remain in use over a considerable period. These are the permanent series, often referred to by collectors as ‘definitives’.

Surprising as it may seem, there was once a time when the only stamps fell into this category. Back in 1840 when Rowland Hill introduced the Penny Black, there was only one kind of adhesive postage stamp. The famous Penny Black prepaid the postage on a letter weighing up to half an ounce, while its less well-known but now much more expensive twin, the Twopence Blue, covered letters up to an ounce. Above that, of course, you had to stick on as many penny or twopenny stamps as required – mainly confined to bulky packets of legal documents (which is why the cellars and attics of old-established law firms have turned out to be such a treasure trove in times past).

Letters could be registered from 1841 onwards, but payment of the registration fee had to be made in cash, the Post Office Solicitor having come up with the decision that registration was not a postal service and therefore could not be prepaid by means of postage stamps. This rather bizarre notion was scrapped a few years later, by which time the fee had been halved to 6d, otherwise it is tempting to speculate that there might have been lots of covers with large blocks of blacks and blues from 1841 onwards. Instead, of course, such covers are of the greatest rarity and command prices well beyond the aggregate value of the individual stamps.

The colour of the penny stamp was changed to red-brown in February 1841, after the colour of the cancellation was altered from red to black ink. In the few short months that the Penny Black was in use over 70 million of them were printed. Quite a good proportion of these stamps seems to have survived and contrary to a widely held belief it is not a rare stamp. Any dealer worth his salt will be able to show you a substantial number of these stamps, including examples still attached to the original covers.

As the world’s first, however, it is a stamp that every collector would like to possess, and it is the astronomical global demand which has boosted its value to its present level.

In various forms, the Penny red remained in use for 40 years and countless millions were used. Perforation s were adopted in the 1850s and security letters were subsequently inserted ion the upper as well as the lower corners. Tiny numerals engraved in the side panels were another feature introduced in the 1860s, and these indicated the plate from which the stamps had been printed. Eventually these plate numbers ran as high as 225. Very few stamps from Plate 77 were issued and these are now worth many thousands of pounds apiece, but even a set of stamps representing each of the other plates would cost quite a lot of money to put together.

The appearance of check letters in the corners also encouraged old-time collectors to assemble entire sheets of 240 for each plate, a colossal task which must have taken a lifetime and entailed sifting through millions of used stamps.

The design of the Twopence Blue was altered slightly in 1841 by the addition of horizontal white lines, but thereafter these stamps underwent the same changes as the penny stamps till 1880 when they, to, were withdrawn. Halfpenny and three-halfpenny stamps were added to the range in 1870 when special rates for postcards, newspapers and printed matter were introduced.

These four denominations constitute the series known to collectors rather inaccurately as the Line-engraveds. Actually it was the steel plates that were line-engraved while the stamps were produced by the recess or intaglio process. The first attempt to produce stamps of a higher value than twopence came in 1847, as a result of an Anglo-French postal treaty which permitted the use of adhesive stamps on mail going to France. For this purpose stamps were embossed one at a time on sheets of gummed and watermarked paper.

This laborious process was entrusted to the Stamping Branch of the Board of Inland Revenue at Somerset House which printed 6d, 10d and shilling stamps. Being struck by hand, one at a time, the impressions often overlapped and there was a great deal of difficulty in cutting them apart, which accounts for the comparative scarcity of nice, four-margined examples.

In 1853 De La Rue began printing revenue stamps, using the typographic or letterpress process, and the following year they were given the contract to produce 4d postage stamps by this method. Gradually De La Rue took over the printing of all the stamps from 3d to £5 by this method and in 1880 this system was extended to the halfpenny to 2d as well – a very lucrative business as these were the most frequently used stamps of all.

Line engraving and recess printing were very costly processes which involved considerable labour and skilled craftsmanship, whereas De La Rue’s typographic process was very much cheaper. The authorities clung to recess printing because it was perceived as difficult to counterfeit, but eventually de La Rue convinced the Post Office and Inland Revenue that their process was just as secure, so long as specially watermarked paper was employed. The argument was tipped in their favour for two reasons.

The first was that their stamps, on thinner paper than the line-engraveds, adhered much more effectively to the envelope. A distressing number of line-engraved stamps was invariably found at the bottom of every mailbag, and people complained when they were forced to pay double on letters which were apparently unstamped.

More importantly, De La Rue touched a raw nerve when they pointed out that there were ways of chemically removing the cancellation mark from line-engraved stamps. They, on the other hand, had perfected fugitive inks which would run if the stamps were immersed in water, far less cleaned chemically, and it was this feature that sold the idea of letterpress stamps to the authorities.