While I was growing up, everyone other than office workers, wrote with pen and ink. By the 1950s I, like most children, had
graduated from a pen which had to be dipped into ink to a fountain pen. Fountain pens could store ink.
The following images are courtesy of Heritage Vintage Pens who sell and
repair such pens.

Old fountain pen with its top screwed on for carrying around.
Note the lever at the side.

Old fountain pen ready for use, with its top unscrewed and pushed onto the
back of the pen. This not only held it tidily, it also lengthened the
pen making its balance better for writing.

Inside the fountain pen, showing the rubber ink reservoir - for
illustrative purposes only as the pen could be filled with ink without
opening it up.
When the pen was empty of ink, It was filled by dipping the nib into ink
and repeatedly using a finger nail to pull out and let go the lever on
the side. This accordingly squashed and released the reservoir drawing
ink up into it. It was full when the process no longer generated bubbles
in the ink.
The flow of ink from this type of pen was smooth resulting in even
writing.
Filling a fountain pen

Ink bottle containing black ink. Photographed in Milton Keynes Museum
Fountain pens had a rubber balloon-like
reservoir inside the body of the pen which stored the ink - see the photos
above. Thus reservoir had to be squeezed
and let go to suck up the ink through the nib from an ink bottle. A lever on
the side of the pen did the squeezing (Much later, ink cartridges were
the norm, which dispensed with the
messy business of having to fill the pen.)
Advantages of fountain pens over ordinary pens
Fountain pens had the
advantage over the old
style pens because they didn't have
to be repeatedly dipped into ink. The flow of ink was smooth and continuous which made the
writing appear much neater.
However fountain pens did tend to leak. Also, like with all pens, we
had to let the ink dry on a page before turning it over or folding it.
Blotting paper was available but never seemed to be on hand when needed
in ordinary homes. Better-off homes and businesses had all these
things ready laid out on desks, often in matching sets.
Styles of fountain pens

Business man's breast pocket with a range of fountain pens and
propelling pencils clipped inside and a white pocket handkerchief - all
the unspoken 'uniform' of his work. Screenshot from an old film.
A range of fountain pens were sold with different width nibs and with
different body colours and decorations. Some were quite expensive and
seemed to be status symbols. Like many status symbols, they were often sold in
plush padded boxes and with matching propelling pencils - a common fall-back
birthday or Christmas present. (Silver propelling pencils also
seemed to be status symbols, but I never saw any that weren't tarnished and
dirty-looking. They didn't appeal to me at all.)
Personal fountain pens
Everyone seemed to be very fussy about no-one else using their fountain pens
because the pressure of a different hand was supposed to spoil the nib for the original
user. I don't know how true this was, but it seemed to maintain the status
symbol image.
This website Join me in the 1900s is a contribution to the social history of everyday life in early to mid 20th century Britain, seen through personal recollections and illustrations, with the emphasis on what it was like to live in those times. It is © Pat Cryer.