The stationer is now officially worried. That's two visits in a row in which I've bought just a solitary envelope. I'd agreed to sell a print of one of my Writers' Workshop cartoons - the one about Franz Kafka's tips for self-promotion - but it has taken me three and a half years to get around to sending it off. There was a massive queue at the Post Office on Seven Sisters Road so I worked out that it would be quicker to get the tube into town, drop off the envelope with the illustration to the buyer, then go for lunch at a nice Italian cafe. I timed it at two hours all in, pretty much the same time as I would have been waiting at the Post Office to buy my stamp.

The person who wanted the print has promised to send me a biography of Franz Kafka, written by her husband. I like the idea of biographies becoming a new kind of currency.