Some 20th century artefacts have largely gone from the modern office, the typewriter and fax machine among them. They have been swallowed by computerisation and the internet. One dead-tree tradition endures: the business card.

Despite strenuous efforts by mobile phonemakers and software companies to replace business cards it them with online contacts, shared like some invisible handshake by Bluetooth or wireless, the business cards remain. As long as you remember to carry them, nothing has improved on the ritual of exchanging rectangles of card stamped with your identity and details.

Business cards are light, portable and open. No need for compatible platforms and software to swap them — you hand them over, perhaps with a little bow if you are in Japan. Nor does the exchange endanger privacy. It is peer-to-peer networking: the only person who sees the card is the one who receives it.