I mentioned buying some refillable brushes last week, and then that they ended up working horribly. It turns out, when assembled correctly and with care, they work really well. I've been putting off writing about it because I wanted to take before and after pictures of the doodling I did, and pictures of the pens and ink and stuff I bought. But I keep not doing it, because being at my house makes me want to melt into my bed and never get up, so it's hard to motivate myself to do extra work there.
This time around I bought ink that I'm sure is the right kind -- non-waterproof, rather than "This doesn't say it is waterproof anywhere." I also got one of those syringes normally used to give babies liquid medicine, to fill the pens with. (The first time around, I made makeshift funnels out of pieces of paper. The ink got everywhere.)
With the new ink, neatly filled, the pens write smoothly and don't bleed into the paper. The problem I was having with ink spraying out the sides of the pen turns out to be what happens when you squeeze way, way too hard, and it's difficult to see what happens when you squeeze the right amount, but it does saturate the brush with ink.
I promise, I'll take photos soon. I'll make a gallery or something.