In the 1950s, Saigon designers tightened the fit of the ao dai to create the version commonly seen today. Trần Kim of Thiết Lập Tailors and Dũng of Dũng Tailors created a dress with raglan sleeves and a diagonal seam that runs from the collar to the underarm. Madame Nhu, first lady of South Vietnam, popularized a collarless version beginning in 1958. The ao dai was most popular from 1960 to 1975. A brightly colored "áo dài hippy" was introduced in 1968. The "áo dài mini", a version designed for practical use and convenience, had slits that extended above the waist and panels that reached only to the knee.