Full slips never go out of fashion; there is always something sheer or clingy in your wardrobe that will look a whole better with a slip. Full slips cover from bust to hemline. Many styles have formed bodices, sometimes with molded cups. An 18'"" full slip is measured from natural waist to hem and falls to mid-thigh on women of average height. It's the perfect length for everyday dresses. For a smooth silhouette, consider a tailored 18"" slip made of modern synthetics with a hint of spandex.