I use whatever specifically labeled hand quilting thread comes in the color I want. I use Gutermann; Coats; Americana. The Americana brand is sold in JoAnn's and does seem to be quite a bit heavier than most other hand quilting threads but sometimes it's the right color, so I'm okay with it. Probably Gutermann is my favorite handling thread but I'm not overly particular. I also prefer Thread Heaven vs beeswax, but that's just me.