When casting off in brioche, you need to take care to maintain the elasticity – especially for something like a snug cowl, where you really don't want to struggle to pull it over your head! A regular cast-off, loosely worked, would probably do the job. But if you take a little trouble, you can do something that maintains the brioche rib, and all its special qualities, right into the cast-off.
Worked as described below, the colours of the cast-off chain will alternate with those of the rib columns, to match the braided cast-on used in Wraparoche. To have them rather line up, switch them around: work brp in FC and brk in BC. Or for a more unobtrusive finish, use just the background colour.
It’s easiest if you are comfortable holding one yarn in your left hand, Continental-style. (This is basically the same as the way I work one-pass brioche.) In this tutorial I am carrying the FC in my left hand. If you need a closer look at any of these pics, just click on them!
1. Bring FC forward and lay it over the LH needle, creating a yarn over.
2. Brp using BC and bring yarn to back.
3. Brk using FC.
4. Pass first stitch worked over second.
5. Repeat steps 1-2 and pass first stitch worked over second.
Repeat from step 3.
To close in the round: cut yarns and draw FC through. Using a yarn needle, draw FC end under the first cast-off stitch and back into the last stitch.
There you go – a neat, stretchy edge that keeps all the bounce, body and structure of brioche.