A variation of stays called “les grand corps”…

… or le corps de cour” was a boned bodice of French Court Dress.  When the shoulder and neck were exposed starting in 1680 with the rounded stays, women realized it was a great way to show off jewelry, laces, and other fancy work.  This bodice was worn with straps off the shoulder, and with enormous panier and train.  It was the obligatory “uniform” of Court dress until about the mid 1770’s.

(Extant: 1750 French “Les grand corps” stays)