I found this idea a while ago at a WeFF show in Carson (?), CA, made by Deanna Deeds. I’ve since wandered down a rabbit hole of Sprang 
I finally found a pattern for making a scarf in twill with sprang. I’m not following the pattern, but using it as a recipe, to try my hand at creating sprang in weaving. I do plan to move on to the true pattern as I get more comfortable with twills on my RH loom.
Setup: 112 ends wound on and threaded for plain weave, 40” warp. I’ll measure two sets of tan with 14 ends, but make them 50” long since sprang can have a greater take up. These tan ends will also be setup as supplementary warps, but threaded thru the heddle one/dent as if for plain weave. I know these stripes will add thickness to those areas, but that’s ok by me.
05-25-2017
I’ve started weaving
I’m using the same green yarn for the weft as I did with the warp.
Plan: Weave a border of 16 weft picks, to match the 16 warp ends outside my tan stripes. Float the tan stripes over the next 16 weft picks. Begin weaving again, using all the warp ends, for 4 weft picks. Stop weaving, remove the weights from my supplemental warp bundles, and start the sprang of the floating tan sections. I’ll then start weaving again, making up whatever pattern seems right.
05-26-2017
I’m almost done with my sample/experiment. My sprang areas are getting more even and consistent, and I’m getting better at weaving my twist-saver yarn in along the sides of the sprang, also.
I’ve got just a bit of warp left - I’ll twist the last area of sprang, then weave the final few weft picks of the last woven section. I’m not sure if I’m going to tie knots and leave a fringe, or twist the fringe, for the edges.
jeen also gave me an excellent idea for a future project using these ideas of sprang on weaving, but I’m keeping it to myself until I can share a project using it 
05-29-2017
It’s off the loom and looks great! It’s roughly 13.5” X 19”. I’ll tie the fringe into knots and wash it to finish it, then trim the fringe shorter.