Giving these stitch holder cords a go to fit-check this sweater.
They're hollow tubes which you push your needle tip into the end of and then slide your stitches onto - faster than spare yarn and supposedly more secure than keeping stitches on needles. I did lose about 20 stitches during transfer so not sure about that, although I think I have the knack now? Anyway, they sort of worked and will also do as more substantial stitch-holders, so for £3 I'm quite happy!
