Page "Fountain pen" Paragraph 8

Progress in developing a reliable pen was slow until the mid-19th century, because of an imperfect understanding of the role that air pressure plays in the operation of pens and because most inks were highly corrosive and full of sedimentary inclusions.

The Romanian inventor Petrache Poenaru received a French patent for the invention of the first fountain pen with a replaceable ink cartridge on May 25, 1827.

Starting in the 1850s there was a steadily accelerating stream of fountain pen patents and pens in production.

However, it was only after three key inventions were in place that the fountain pen became a widely popular writing instrument.

Those were the iridium-tipped gold nib, hard rubber, and free-flowing ink.