I'm not that old, but I remember in grade school we had flip-top metal desks with wooden tops, and inside this sort of desk was a round bracket to hold an inkwell. Older grade school and high school kids at the time were using those newfangled "cartridge" fountain pens. With these pens you had a little plastic ink cartridge you popped in, instead of having to dip the pen into a bottle of ink.
“...those newfangled “cartridge” fountain pens...”
I had a fountain pen, but it had to be filled from a bottle of ink. Never forget the time I spilled a bottle of ink in the on the carpet in the middle of the living room. But we had a neighbor who owned a dry cleaners; dad called him and got it all out, no stain...and I did not get my butt beat. :)