This nightgown is an example of one type of informal clothing worn by men in the early 19th century. Nightgowns were worn over shirt and breeches, in the privacy of home before noon or late at night. They first appear in the male wardrobe in the mid-17th century, inspired by the kimonos given by the Japanese shoguns to the directors of the Dutch East India Company. During the 18th century nightgowns evolved into several different shapes, from the simple T-shape of the original kimono to others cut more like the European coat, as in this example.
The tufts of black wool on the cream wool fabric are meant to imitate ermine. This nightgown comes from wardrobe of Thomas Coutts (1735-1822), the founder of Coutts Bank.Cream wool nightgown/dressing gown with black wool tufts simulating ermineM, 1820c, English; White flannel, simulated ermine. Coutts