At the very beginning of the 18th century the stays were long in the front (forming a "V") but remarkably shorter at the back.
To make sure that the corset would stay in place and constantly provide the lady with the desired small waist it had to be made out of rather hard materials. A gentlewoman's stay would consist of several layers of linen which had been stiffened with a sort of paste. Besides, several "channels" would be hand-sewn into the linen - the channels would be stiffened with whalebone. Towards the end of the 18th century the old-fashioned stays - that would be very stiff and painful to wear - had been replaced by a more relaxed style that would put focus on the breasts. Horace Walpole noted that a lady had been severely bruised by her corset!
Even though the stay was considered an integrated piece of underwear it would still be lavishly decorated with silks. When wearing a corset a woman could not bend forwards at the waist but it was actually very healthy - it would mean that women would always lift with their legs thus sparing their backs.
|Pretty example of an 18th century stay (Metropolitan Museum of Art)|
|A rather good description of how a stay was laced|
|French, between 1735-1770|