I just have to say, I love my new fountain pen. This pen.
My red and gold Jinhao fountain pen that Odysseus got me for our anniversary completely rocks. Their medium nib seems to be more of a fine nib (which gets me curious about what their "diamond fine" nib is like). The entire pen, except for the refillable cartridge and the back part of the nib where the ink channels down the the point, is metal. The pen is startlingly weighty. Not flimsy at all.
I've also discovered that I like the refillable cartridge quite a lot. I got some green ink for this particular pen--just because. I inspected the nib (no detritus left from manufacture or from shipping), and immediately filled the cartridge...and it was actually a little easier than puncturing a disposable cartridge with the back end of the nib, and not much messier. Along with that, a package of cartridges for the Parker pens I have (Parker Vector, which is okay, but not spectacular, despite the one I bought in grad school in '03 still working like a champ) costs around $5, and I can't find them locally. They hold maybe a mL of ink, and last about a week of heavy use (and yes, they do get heavy use--I hate ball-points and roller ball pens). They come in blue or black, so not a lot of choice. A 50 mL bottle of ink also costs around $5...and come in about thirty different colors of India ink at Hobby Lobby. Yes, I'll have to refill the cartridge a bit more often, but...I think it's well worth the trouble, and easily worth it financially.
I have learned something interesting, using this pen: heavier pens make for less pain in the bad joint at the base of my index finger. Yes, it makes the rest of my hand more tired and faster, but something about the balance and weight makes it easier to control, and I end up not using that specific joint as much as I do when I'm using my plastic fountain pen.
I really, really love this pen. I don't think I will ever buy a plastic pen again. Especially not since the Jinhao pens are so relatively inexpensive.
52 minutes ago