S is for Surface printing
When De la Rue started printing British stamps in 1855 the process they used was called surface printing to differentiate it from the recess-printing technique used by Perkins Bacon on earlier stamps. When De la Rue lost the stamp printing contract to Harrisons in 1911, the printing process was called typography (or ‘typo’) by stamp collectors and in the catalogues. Yet ‘surface’ and ‘typo’ are the same process and the terms mean little to professional printers, who would use the term ‘typographer’ to refer to someone who assembles loose letters of type into words and paragraphs as in an old book or leaflet.
The surface printing process involves the stamp image being engraved and impressed in wax or in a soft lead a number of times. On this surface copper is deposited by electrolytic action – when an electric current is passed through a copper solution it is deposited on one of the electric terminals. The copper shell is removed and given a strong backing and a hard surface, often by nickel plating. Harrisons’ recipe for doing this might be different from that of De la Rue, but essentially the processes are the same.
The stamp was printed from ink applied to the high points, the surface of the design, not the grooves, as in recess printing. It was easier to lay down the stamp impressions accurately on the printing plate and it was printed dry so there was no shrinkage, therefore perforation was easier. There was also fewer idiosyncrasies on the printing plates, and so far fewer varieties for the philatelist to collect.
Eventually De la Rue took over the printing contract for all British stamps, introducing chalksurfaced paper as added security. Printed on this paper the stamp would smudge if the cancellation was cleaned off. For the Colonies they produced the key plate issues where different colonies shared the same stamp design but with different country names, to save cost. Sometimes the country names were just overprinted in printers type, true typography! They even printed the Jubilee issue of British stamps bi-coloured but by 1911 the stamps were thought old fashioned and the contract went to Harrisons.
The new King, George V, himself a philatelist, wanted a more lifelike, photographic image of himself on the stamp but this didn’t work and we reverted to an engraved profile head, like that of the first stamps of Victoria. Stamps with a more realistic image had to wait for the perfection of the ‘photogravure’ printing process in the 1930s.