"A leather tanner, Harvard-educated lawyer, and inventor, John Loud... While tanning leather, often needed to mark a point to cut...a fountain pen made this process quite messy...He designed a writing tool that had a small rotating metal ball clutched in a socket."
"During summer, the ink from the first ballpoint pens overflowed. In winter, the ink didn't flow and froze. At high altitudes, ink would seep out of the pens under the change in pressure. Inventors came up with creative solutions to try and fix these issues such as springs and piston-pressurized ink reservoirs or capillary action to make the ink flow without gravity. But nothing quite delivered a guaranteed writing experience."
"BÃró noticed that the ink used on newspaper printing dried almost instantly with no smudges...Water-based ink leaked out of the pen and needed to saturate into the fibers of the paper (which is why dry time was critical). But oil-based ink sat on top of the paper, preventing it from bleeding through the page and allowing it to dry almost on contact...his brother...aside from being a dentist, was also a rather talented chemist... Their patent was for
1) A system of getting the ink from the reservoir to the rotating ball. 2) An airtight reservoir for storing a particularly dense ink.
3) A sealing mechanism in the metal ball that would prevent ink oxidation/evaporation.
4) A free ball nib.