This is a new stitch for me. I’ve wanted to experiment with some of these threaded stitches every since I worked on couching a while back but I’ve never had a reason to do it (or I’ve just plain forgotten).
This is an amazing example from hand embroidery network of what you can do with the threaded/whipped backstitch. It looks like ricrac and would make the most fabulous flowers.
Here is a lovely post with photos on how to do the whipped back stitch
and here are photos on how to do the threaded back stitch.
And here are my how-to videos: (sorry they are a little shaky today!)
the whipped backstitch
the threaded backstitch