|Lewis Walpole Library|
This print from 1775 shows us a woman at home wearing undress, having her corns cut!
This zoomed in view shows us she is wearing a jacket in the French style. This excerpt from the Lady's Magazine, May 1775, gives us the clue as to what is going on.
The term nightgowns is referencing English fitted gowns, telling us that now they flying back like a French jacket. This jacket fits the description, it is not closed and appears loose to the body and has a sash around the waist. Dovetailing perfectly to the description given in the Lady's Magazine. Is this the transition to the "zone" gown?