Thanks, Bronze!
Yeah, I'm going for micro coil.
I got 2mm silica. I also got "Double Twik", which is 2mm, but swells to 4mm when wet. Is that ok? I also got the Twik with only 1 cotton strand. I'd assume that swells ~1/2, but that's just a wild guess. I guess we'll see.
I don't have a...