Notes and pictures gathered for Lady Sybil's New Frock
Notes from the show's costumer regarding this costume: Of Sybil's shocking new outfit, Fellowes explains, "no woman of her class, before Poiret's harem look, had ever been seen in trousers." Buxton describes the look's origins: "I found a long strip of original fabric set on gold net, which was so fragile it had started to split, and used that for the top and sleeves. The blue peacock bodice came from Alfie's Antiques market. The beaded belt was found at a vintage fair and the blue silk chiffon used for the trousers came from Shepherd's Bush Market."
Sleeves and upper bodice
This is the fabric described as sitting "on gold net". With that, and the metallic embroidery being the only details I have to work with, I started looking for lace that might be a good match.