I just read this post, about refillable brush pens, by Jonathan Case.[1. By the way, his name sounds familiar, but I don't recognize any of his comics' names, so if he's known for being a massive asshat or abuser or something let me know and I'll remove the link and named reference.] Consequently, I'm buying a set of Pentel Waterbrush Pens. These pens are part of a category of art supplies that I had no idea existed. I was looking, not for them, but for better options in felt-tip brush pens, because my favorite ones come in a small range of colors, are very expensive, and one of them is out of ink, and the new ones I just bought don't suck, exactly, but are markedly disappointing in the context of the other pens.
I will report back with the quality of the new pens, probably on Friday.