MicroQuilter is a 100wt 2-ply extra fine polyester thread designed for invisible machine applique and detail quilting. It is an extremely fine thread that can be sewn with a very small needle. 60/8 or 70/10 for home machines or 14 or 16 sized needles for long arm machines.
I use this thread to hand applique my quilt labels to my quilt and to topstitch Dresden plates. It is an excellent thread for hand applique, but also has a way of almost disappearing when using it to topstitch if you prefer your thread not to show.
I use a milliners needle to hand sew with this thread. The milliner's needle has a very small eye making the thread much less likely to slip out.
I talk about this thread: