M. de Garsault, Art du Tailleur
(1769), plate 12 (detail).
Source: gallica.bnf.fr / BnF.
The stays in Garsault's 1769 "Art du Tailleur" are of a very different cut compared to Diderot's 1771 pattern. Garsault's cut has a more comfortable fit in the lower back, and can be adjusted to improve bust support.
Garsault doesn't depict individual pattern pieces, but we can use his
illustrations and written information to alter another pattern into
his cut.