During the middle of the eighteenth century, a style became popular in France and adopted by the fashion conscious elite. It became known as the robe à la française in France, the mantua in England. According to Madeline Delpierre, that was due to a French engraver by the name of Hubert Gravelot. He had returned from England after twenty years to France and published a series of fashion plates that aided the popularity of the style.
It became very fashionable particularly at Court. The gown had a panel in the middle of the back that went from neck to hem in one piece. The panel had pleats at the top and waist which flowed freely into the skirt. At the front the skirt was detached to the bodice forming a point slightly below the waist opening to reveal a separate stomacher.
The painted silk gown (above) revealed the presence of a plant gum binder and four colors were used for the palette: red and brown lake, prussian blue and gamboge. These details identify the dress as most likely European. Details given are England, material either Dutch or German.
But what did it look like on...(see left).
Ref. The Fashionable Past: a blog of costume and design.
The Metropolitan Museum of Art