Mr William Hogarth, in 1753 published "The Analysis of Beauty" which describes in detail Mr. Hogarth's opinion on what constituted visual beauty and good taste (quite a controversial topic of the time from a controversial artist).
The "S" curve, a serpentine line found in many elements of 18th century art, architecture, furniture and textiles constituted Hogarth's famous "Line of Beauty". In this plate, Analysis of Beauty (Plate 1 of 2), the fourth pair of stays (center) is the ideal shape, having all of those elements that are pleasing to the eye including: fitness, variety, simplicity, regularity, quantity and intricacy.
This plate shows us, the modern staymakers, what the ideal stayed figure should achieve from a visual standpoint while wearing stays. Too straight (number 1) is to be avoided as not pleasing to the eye, while too curvy (number 7) is also not attractive with the exaggerated curves to back and front, therefore striking a balance between the two extremes (number 4) is our goal when fashioning the stayed body.