1765-75
The pet en l’air was a short, open jacket intended to be worn at home, perhaps as a lady spent a morning writing letters before dressing for the day. This reproduced gown of orchid-colored watered silk would be worn by a woman of the “better sort” of Philadelphia just prior to the American Revolution. The gown was sometimes called a French jacket. The original French meaning of pet-en-l'air is opening, sometimes interpreted as peek-a-boo. The complicated outfit made it impossible for a woman to dress herself, so only someone with the resources to hire a maid could wear this elegant gown.
The jacket is lined with white cotton, except the pleats in the back. Beneath the pleats there are laces to make the bodice fit more closely to the figure. A sheer kerchief frames the neck and backs the tablier (apron-like) front which is fastened with concealed hooks. The sack-backed jacket is worn over a floral silk petticoat. Both have slits through which she has access to her pockets beneath. The pocket was tied to a string that went around the waist. Lucy Locket of nursery rhyme fame lost her pocket because her string came untied. During the 18th century petticoats were made to be seen and didn't become undergarments until the 1820s. A large hat covered the extreme hairdo.
About the waist is a ribbon girdle from which hangs a chatelaine. This kept necessities such as needles, pins, and perfume at her fingertips. Other items were carried in her pocket. A cap and hat were essential (not included in photo).
Hoops, often of whalebone, helped achieve the popular "wide side-to-side" silhouette by extending the petticoat out on the left and right side. In the late 1770s, the hoops had become smaller, which made going through doorways easier. A lady must stand tall and straight; to help her, she wore stays or a corset. These are stiffened with metal and bone and laced tightly.
Click photo for detailed views.
Additional sources:
https://brocadegoddess.wordpress.com/pet-en-lair/
http://fransewing.blogspot.com/2013/11/18th-century-jacket-pet-en-lair.html
