I've had a fountain pen for years. Since 1976, to be exact. Sterling silver, it has served me well, but it's getting darned expensive to buy its cartridges. Vaguely, I remembered an ink well my grandmother gave me a zillion years ago. Sterling silver, it's a remnant of another age, but it has held ink for me. Since my Parker came with a refillable cartridge, I would buy colored inks and fill the pen up from this well. When I felt the urge to write in emerald green, I'd go at it.
Lo and behold, I found the ink well. It's a bit battered (heaven knows how old it is), and it has a half-glass, half green baize (I think that's the word for the fabric) bottom. You can see inside where there's a metal well (maybe tin?) sitting in the glass, and the silver is formed around the glass. You stick the pen in the well, pump the cartridge holder vigorously, and voila! Ink.
Now I have to find ink in a jar. I'll probably have to shop at an art supply store, but we writers are artists, right?
There's nothing in the world like watching words flow on the page from a beautiful pen. I'm gonna have a trip down memory lane. If I can find the ink, that is.