Blonde Girl Wearing A Red Corset

The purpose of 18th century stays was to support the bust, confer the fashionable conical shape while drawing the shoulders back. At this time, the eyelets were reinforced with stitches, and were not placed across from one another, but staggered. This allowed the stays to be spiral laced. One end of the stay lace is inserted and knotted in the bottom eyelet, the other end is wound through the stays' eyelets and tightened on the top. Tight-lacing was not common in this time period, and indulged in only by the very fashionable. Stays were worn by women in all societal levels, from ladies of the court to street vendors.
At this time, there were two other variants of stays, jumps, which were looser stays with attached sleeves, like a jacket, and corsets.
Corsets were originally quilted waistcoats, worn by French women as an alternative to stiff corsets. They were only quilted linen, laced in the front, and un-boned. This garment was meant to be worn on informal occasions, while stays were worn for court dress. In the 1790s, stays fell out of fashion. This development coincided with the French Revolution, and the adoption of neoclassical styles of dress. Interestingly, it was the men, Dandies, who began to wear corsets. The fashion persisted thorough the 1840s, though after 1850 men who wore corsets claimed they needed them for "back pain".
Stays went away in the late 18th century, but the corset remained. Corsets in the early 19th century lengthened to the hip, the lower tabs replaced by gussets at the hip. Room was made for the bust in front with more gussets, and the back lowered. The shoulder straps disappeared in the 1840s for normal wear.