Lutz and Patmos commissioned several designs by "guest designer" Jane Birkin in heather gray or mocha organic cashmere; this 3/4 sleeve sweater is $695 from Barney's.
I won't be buying, as largest size offered on the site is medium, but I would love to try it, as it's a ringer for a Calvin Klein cotton interlock knit top I bought circa 1982. I think I paid $135 for it, a fortune then, but when I put it on, it was so magically cut that it changed my whole upper body. With that piece I learned the power of perfect cut on a deceptively simple garment.
It could be overpriced; you can find similar deep V's on a few cashmere sites, though the necks tend to be narrower, more masculine. Jane's looks harmonious and balanced. She designed it so it can fall off one shoulder. And zen zee French guy can kees eet. Or is it just that I love Jane in hers, and so idealize the garment?
She also designed a tank for the collection, and wears the two together. Vraiement belle, Jane!