I've knit this floaty cowl from a lovely soft, light mix of Suri alpaca and silk. Although the yarn is fine and I've used a lacey tuck stitch, the long alpaca fibres form a soft halo, making this cowl a lot warmer than you might expect for it's thistldown weight (about 26g, less than one ounce, including the buttons).
This cowl is long enough to wind around your neck twice or it can hang in a single, elegant loop. I've closed it into a loop on the diagonal, using little mother of pearl buttons.