This autumn I’ve been showing people my flong. Control yourselves. A flong is a mould taken from a page of type by pressing it hard into a sheet of papier-mâché to create a blind impression. You can then pour hot metal over your flong to cast a copy of the typeset page. (This is known as a ‘stereotype’ or a ‘cliché’, to use these words in their original senses.) Because it was made from malleable material, a flong was a convenient intermediary for turning a flat page of type into the semi-­cylindrical shape required by the huge newspaper presses of the 20th century, whose printing surface was a spinning drum.

On the whole, newspaper flong is ephemeral. It comes into being at night, invisibly bearing tomorrow’s news, before being destroyed in the morning. I don’t know why mine survived. I found it at auction: a Times frontpage from 1982. It hangs on the wall of my office at university, a white sheet on an institutional white wall. But in the raking afternoon sunlight, the shadows of old news, old crimes, begin to re-emerge: ‘PEKING REJECTS ACCUSATION BY BREZHNEV’, ‘A MINIBUS BLAZING IN A SAN SALVADOR STREET’. The images accompanying these headlines and captions are more enigmatic. To the naked eye, the faint planes of inverted halftone dots, of minutely different grades of shadow, resist perception. The scenes they depict remain open to interpretation.

‘The detective novels were always on his bedside table,’ explained the housekeeper. ‘The professor always slipped his matchstick ends between the pages.’ You can almost imagine the story that follows. Cosy crime. A country house whodunnit. If a matchstick appears in act two, there must be a fire by act