George Mackie is 100 years old today. I first met him a few years ago, at a party celebrating an earlier birthday. My father, Peter Campbell, was in his last year, and not feeling up to the train. He asked me to drive him and my mother to George’s house in Lincolnshire. Peter and George had been writing to one another since George had sent what he describes as a ‘fan letter’ praising the design of the London Review of Books. They had both had long careers as typographers and illustrators. If these jobs are done well, it’s often by being as unobtrusive as possible. As Beatrice Warde argued in ‘The Crystal Goblet, or Printing Should Be Invisible’, ‘almost all the virtues of the perfect wine-glass’ – ‘crystal clear’, ‘thin as a bubble’, ‘transparent’ – ‘have a parallel in typography.’ George thinks that as his eyesight deteriorated, his typography improved. Some of the lost clarity of vision can be repaired by making clearer pages.

When you pay with a fiver, a tenner or even a twenty, the chances are the shop assistant barely gives the banknote a glance. But hand over a fifty-pound note, and its half a ton to a pony that the recipient will make a show of holding it up to the light to make sure it’s genuine. Most people probably only look for the wire and the watermark. The Bank of England lacks complete confidence in these long-established devices, so it now includes many other security features. Without them, counterfeiting would doubtless be a bigger problem than it is: according to the figures for 2009, only one note in every 50,000 in circulation was a fake; 95 per cent of them were twenties. One-pound coins are much easier to forge: about one in 36 of the 30 to 40 million circulating is reckoned to be counterfeit.