So I was tired and unwell and it seemed like a good idea: just take a ball of nice wool cotton and keep knitting i-cord until the ball runs out.
And it was a good idea. It turned out really nice, it just took a while to knit.
I knit it up on 3.0mm needles in a flecked grey which gives it some interest in terms of texture. It measures over 10m long and I have been wearing it simply looped around like a coil of rope. I tried plaiting it but it ends up too thick and stiff with no movement. I'm planning on making a leather clasp to cover the knot at the back where I simply tied the two ends together. I've got a small scrap of deep red leather that will look great as the clasp.