By the mid 1870s, the Penny Black plate numbers were nearing the 200s and the Twopenny Blues were up to plate 15. The series looked as if it might go on forever. But in a few years, everything changed.
These stamps had been produced in essentially the same way since 1840. But it was a craft process in an industrial age. Line-engraving was great for producing images with intense colour and a wealth of fine detail, but it was not ideal for volume production. Attempts to mechanise the process in the 1850s had failed, and it was still manual work. The paper was handmade – of variable thickness – and supplied untrimmed. The sheets were printed wet, so they tended to shrink. And the degree of wetness varied from sheet to sheet, so the shrinkage was uneven. This meant that the printed sheets had to be sorted by hand before being fed into the perforating machines.
As far as the public was concerned, the stamps were looking old-fashioned. Britain had progressed enormously
