In 1938, László Bíró, a Hungarian journalist, invented the ballpoint pen, because he was sick of smudging the ink from his fountain pen.

Inspired by the rollers of the printing press at his newspaper, he came up with the idea for a small ball at the end of the pen, which would stop ink from leaking.

Thanks to a chance meeting with the Argentine president Agustín Justo, László was invited to Argentina to manufacture his pen.

They soon took off and now around 15 million of them are sold every day around the world.

Rachel Naylor speaks to László’s daughter, Mariana Bíró.

(Photo: Ballpoint pens. Credit: Bernard Annebicque/Sygma/Sygma via Getty Images)