The Ballpoint Pen Took Decades and a World War to Get Right

US2390636 was granted on December 11, 1945, to László Bíró (and his brother György), the patent that is usually credited with finally making the ballpoint pen work. The idea was not new. A ballpoint had been patented in the United States as far back as 1888, by John Loud, for marking leather — and had been patented and re-patented by various inventors in the decades since. Every version had failed for the same reason: the ink.

The mechanism of a ballpoint is simple and appealing. A tiny ball, seated in a socket at the tip, rolls as you write, picking up ink from a reservoir on its top side and depositing it on the paper on its bottom side. The ball acts as its own constantly renewing nib, and — unlike a fountain pen — needs no delicate split nib, no blotting, and no refilling from an inkwell. The problem was that fountain-pen ink was too thin: it leaked past the ball and flooded the page, or it was too thick and the ball dragged and skipped. No one had found ink with the right properties.

The editor's insight

László Bíró worked as a journalist and editor in Budapest in the 1930s. He spent his days around printing presses, and he noticed that the ink used in newspaper printing dried almost instantly and smudge-free — completely unlike the wet, slow ink in his fountain pen, which constantly smeared his editing marks. He wondered whether that fast-drying, viscous printer's ink could be made to work in a pen. But printer's ink was far too thick to flow through a conventional nib.

The ball was the answer to that. A rolling ball could pick up thick, quick-drying ink and lay it down in a thin line, metering it precisely — the very property that had doomed earlier ballpoints with thin ink became the solution with thick ink. Bíró, working with his brother György (a chemist, who formulated the ink), spent years refining the ball-and-ink combination.

War, escape, and an air force

The Bírós fled Europe as fascism spread, eventually settling in Argentina, where they filed the 1943 patent that led to US2390636 in 1945. The invention's first big break came from an unlikely customer: the British Royal Air Force. Fountain pens leaked at high altitude — the pressure changes made them flood — but a ballpoint did not. The RAF needed pens its navigators could use in unpressurized cockpits, and licensed the Bíró design. The pen went to war before it went to the stationery store.

The commercial rollout was chaotic and, for Bíró, largely unrewarding. An American businessman named Milton Reynolds saw a Bíró pen in Argentina, copied the concept, rushed a version to market in the United States in 1945 (beating the official licensees), and made a fortune before the fad briefly collapsed under a wave of leaky, unreliable knockoffs. Bíró had sold many of his rights and saw little of the eventual windfall. It was Marcel Bich, later, who industrialized the ballpoint into a reliable, disposable, dirt-cheap product — the Bic pen — and turned it into one of the best-selling manufactured objects in human history.

In much of the world the ballpoint pen is still simply called a "biro." It is one of the few cases where the inventor's name became the common word for the thing, which is a kind of immortality, even if it was not the kind that pays.

See the original

The full text and figures of US2390636 are on patents.us.