Sprang - a very old technique
Sprang is a very old braiding technique which is done with stretched yarns. Usually this is done within a frame. There are other sites with general information about this technique.

Carol James has a series of very good instructional videos about the technique of sprang at her website. See also this video from her at You Tube. She also offers online sprang classes about the basics of sprang and some special sprang techniques.
Sylva Antony Cekalová has made another very interesting website about sprang.
I also like to recommend you the site of my Japanese friend Chieko Aihara. Her artistic way of making sprang is very inspirational to me.

I myself have also a You Tube channel about sprang. You can find me there as Sprangria. 
This video of me is about how to prepare for sprang.
I have also made a video about some of the frames you can use for sprang, including a very simply one, made of cardboard. There are many more video's of me about the technique of sprang and I hope to add more to it.

There is also a group about sprang at Facebook.