Stamp Collector

75 MAY 2020 www.allaboutstamps.co.uk PHILATELIC FOCUS Letterpress printing is the opposite of line engraving. The image area is raised up, not dug in and the raised type receives a coating of ink which is then transferred to the surface of the paper. It is not absorbed into the sheet as it is with line engraving. Its earliest form is woodblock printing, or xylography, which was developed in China around the 2nd century AD, where the image is carved into a single block of wood. It was revolutionised by Gutenberg in the 15th century, with the invention of movable type. This led to a boom in the production of books and other material and many early printing presses were originally wine presses, adapted to a new industry. They soon developed. The first all-iron hand-fed press was introduced in 1798. In 1814 came the first steam-driven cylinder press. The type was inked by rollers, not an inking ball and the paper revolved on cylinders. Printing costs plummeted as a result. This simple economical process was ideal for the production of stamps. France, for instance relied entirely on letterpress printing until 1928, when recess-printing was employed purely for the production of commemorative stamps. These were of increasing importance to the French treasury and the machines that printed the ‘Sower’ could not achieve the quality required. Britain made the journey in reverse. And the prime driver of the change was the GPO’s continuing concern about the cleaning and re-use of stamps. After experimenting with embossing, they needed higher value stamps that could not be cleaned or easily forged. De La Rue came up with the answers in an outstanding engraver, Ferdinand Joubert, and with singly-fugitive inks. These would dissolve in any chemical that could remove the cancellation and explain why the early surface-prints sometimes look a little pallid when compared the intense colours of a line engraving. However, there is no one way to print by letterpress and workshop practices around the world started and evolved differently, so this article will look most closely at De La Rue. Surface printing De La Rue used hand presses for British stamps until 1880, when they began printing the four low values from ½d to 2d. The engraving on these was coarser than on the previous surface prints, so the vast quantities required (1.46 billion 1d Venetians) could be hammered out quickly. De La Rue’s plate-making methods were copied from a French engraver, Anatole Hulot. First, they produced a single master die, which was engraved in reverse. (Inked areas down). This was transferred to lead matrices: pieces of metal cut to the size of the finished stamp. The lead was forced into every part of the die, using an embossing press and the matrices were butted up together in a frame to form a printing plate. Gutta Percha – a latex produced from Indonesian trees – was also employed. The next stage was electroplating, when the frame was given a thin coating of copper. This was backed up by type metal (lead, tin and antimony) to form a printing plate. In 1858, another Joubert worked out how to coat the printing plates in steel, which greatly lengthened their lives. When plate numbers and corner letters were required from 1862, the die had holes drilled in it to take the relevant steel slugs. This was an exacting job. They switched from white corner letters to coloured corner letters in 1875 as these were easier to produce but De La Rue were glad when this time consuming and largely pointless process was abandoned. Preparing for print Each new printing plate still needed a lot of work before it started printing stamps. Firstly, the plate had to be made true, with all the relief elements at the same height and the surface perfectly parallel with the base; this process was known as ‘slabbing’. A single craftsman, the slab hand, would work with hammers and punches on the back of the plate until the relief areas had been raised before the back of the plate was skimmed flat. The next stage was the make-ready, which ensures the plate and the machine were set up correctly together. In stamp printing, the most exacting part of this work is called decoupage. The printer took a first proof and examined it carefully so see which stamps had received too little ink due to lack of pressure, or were smudged and distorted because of too much. He would then take a second proof and cut out the stamps where there was too much pressure, before cutting up another sheet and using individual stamps to apply extra thickness to the stamps that had too little. This decoupage sheet was than inserted in the backing for the sheet to be printed. Another proof was taken and carefully examined, and any pale areas received another layer of packing ► Stamp printing in detail LETTERPRESS This month, David Bailey looks at letterpress printing.Also known as relief printing, typography or surface printing, letterpress is the oldest printing method and was the dominant process for stamp printing for nearly 100 years De La Rue’s first British stamps were the revenue stamps of 1853, which were more intricately engraved than the later postage stamps (images courtesy of IB Red Guy)