Thin thread ~ InvisaFil 100wt polyester by WonderFiL
Each mini-pack contains six spools of 400m each.
This is perhaps the thinnest thread I've ever seen and is my "go to" thread when I don't want stitches to show. Where some quilters use monofilament (I'm not a fan), I use InvisaFil. It's fantastic for quilting in the ditch, invisible hand and machine applique, hand finishing binding, and my Piping Hot Curves technique. Free motion quilters enjoy it too in order to show off the quilting's contours without a "thready" look. This poly thread will not melt when exposed to extreme heat and/or steam. I've tried!
I suggest using a 60/8 Microtex needle with regular 50 or 60wt cotton bobbin thread though some report success with a fine thread in the bobbin as well.