“Gutenberg invented his printing press around 1440; the modern paper jam was invented around 1960” says Joshua Rothman in a piece entitled “Why paper jams persist” at The New Yorker.

Unfortunately neither clause is true. Gutenberg didn’t invent the printing press — he invented movable metal types for use in a pre-exisiting wooden press. Nor was the paper jam invented in the 1960s: we’ve been contending with them for hundreds of years.

All too often a printing press will suffer a paper jam. It may be more likely on a sheetfed rotary press* than on a flatbed press; though plenty of paper jams of course occurred on flatbed presses before the rotary press was developed in the middle of the nineteenth century. Mechanization is the big bugaboo. Jams on a wooden press being fed by hand are rather unlikely: things just go too slowly. I well remember watching the printing, by flatbed sheetfed letterpress, of an extremely thin bible paper. The paper delivery system on a flatbed press relies on the weight of the sheet of paper to cause it drop quickly from the delivery platform onto the press bed. But this paper was so light that it’d lallygag about on its drop and gently flutter down into position. Miraculously the pressmen concerned were able to time their activity to get this to happen every time with total accuracy. But error lurked always just around the bend. Slight misalignment, slightly late arrival, a bowing in the paper which may not have settled down quickly enough — any of these, and other freaks lay in wait for the pressman who momentarily looked away. A misaligned sheet may catch on some projection on the press and cause a pile up of crumpled paper as sheet after sheet behind it rushes on to join in the chaos.

The paper jam is another of these tweaks to old technologies which have to be made in order to allow a new bit of whizz-bangery to work. One of the glories of nineteenth and twentieth century craftsmanship was exactly this victory over metal, entropy, and gravity in order to get high levels of production out of recalcitrant machinery. At the junction between a new technology and the physical world lurk trolls. Sort of like Jimmy Speckerman asking Leonard Hofstadter’s help to bring to life his “invention” of glasses which will enable you to watch non-3D movies in 3D. Jimmy knows Leonard is the smartest person he’s ever met, so that he can obviously make the 3D glasses work. But the mind, even Jimmy’s, can outpace the laws of physics. Another familiar example of technology/ physical world conflict can be seen in the fact that from time to time you won’t be able to recharge your iPhone because of the lint accumulated in its tiny charging socket. The phone is of course designed to be carried in your pocket, but the lint gets into the charging port because you carry the phone in your pocket. Pockets, being made of cotton cloth, slough off cotton lint. The hi-tech solution is carefully to scoop out the fluff with an unbent paperclip!

Despite my carping, the New Yorker story is well worth reading, and provides fascinating insight into the workings of R&D at a big company.

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* Cylinder presses had been used for printing fabrics since the 17th century. Early patents involved horses (or water or steam) rotating large circular engraved copper cylinders. But what was really needed for printing anything other than pictures was a stereotype process. Without such a thing gravity would ensure that type would just fall onto the floor after one rotation of the press. See Mr Applegath’s ingenious interim solution. Paper jams look rather dramatic on a web-fed rotary press: crumpled paper piles up fast.

EdwardLloyd.org provides copious detail on the development of the rotary press.