I believe the herringbone stitch is a sewing technique to insert elastic into waistbands. I think you sew "around" the elastic (not through it) to keep it in place but let it retain its elasticity. I bet a sewing stitch site would be a good place to find out how it's done.
I'd decided it was a sewing stiitch Yvonne but have been trying work out how to do it while incorporating the stitches I have on the stitch holders. I may have to cast off first although the pattern doesn't say to do that :rollseyes:
Thanks for the site info Amy - really clear instructions - I have used this for hemming before (while sewing that is). And thanks for the welcome too :D