The ink used in a fountain pen, the ballpoint’s predecessor, is thinner to facilitate better flow through the nib—but put that thinner ink inside a ballpoint pen, and you’ll end up with a leaky mess. Ink is where László Bíró, working with his chemist brother György, made the crucial changes: They experimented with thicker, quick-drying inks, starting with the ink used in newsprint presses. Eventually, they refined both the ink and the ball-tip design to create a pen that didn’t leak badly. (This was an era in which a pen could be a huge hit because it only leaked ink sometimes.The Bírós lived in a troubled time, however. The Hungarian author Gyoergy Moldova writes in his book Ballpoint about László’s flight from Europe to Argentina to avoid Nazi persecution. While his business deals in Europe were in disarray, he patented the design in Argentina in 1943 and began production. His big break came later that year, when the British Air Force, in search of a pen that would work at high altitudes, purchased 30,000 of them. Soon, patents were filed and sold to various companies in Europe and North America, and the ballpoint pen began to spread across the world. Businessmen made significant fortunes by purchasing the rights to manufacture the ballpoint pen in their country, but one is especially noteworthy: Marcel Bich, the man who bought the patent rights in France. Bich didn’t just profit from the ballpoint; he won the race to make it cheap. —The Atlantic