Miniskirts and dresses were perfectly paired with Quant's tights and underwear range, one of the first lines produced using the Mary Quant name under license. She also created the skinny-rib jumper (apparently inspired by trying on an 8-year-old's sweater for fun) and, in 1966, invented hot pants. Capitalizing on the 1960s' love affair with new materials, she was one of the first designers to use PVC, creating wet-look clothes and different styles of weatherproof boots in her footwear range, Quant Afoot.

As London's boutique scene was still blossoming, Quant was cementing her position as a commercial and cultural powerhouse. In 1962, she signed a lucrative design contract with US department-store chain JC Penney. In 1966, she was awarded an OBE and published her autobiography, Quant by Quant. The following year, she opened her third shop on London's New Bond Street. By the end of the decade, Quant was the UK's highest-profile designer and had achieved unprecedented reach in the market; it was estimated that up to 7 million women had at least one of her products in their wardrobe, while thousands more sported the super-modern shades of her Daisy-badged cosmetics range.