Greg Shea asks: "Do you have experience drawing/sketching with a refillable old style fountain pen? (The kind where you draw ink into the pen to refill it, not the kind that uses cartridges). I'd like to fill a pen with walnut ink, so I can use it to to do drawings with addad watercolor. I usually use dip pens with crow quill nibs, but they can be a pain to use and to carry around."
Jinhao and Baoer are both inexpensive and refillable.
My favorite is the piston cartridge that comes as an accessory with Waterman pens, such as the low-end Phileas brand. You can get the converter as a separate item if you already have a Waterman pen. You can also refill the cartridges with a hypodermic syringe, which is cleaner than through the nib refills.
Previously: How to Refill a Fountain Pen