Crafting a youthful and contemporary appeal, the Sonia by Sonia Rykiel label was launched by heiress Nathalie Rykiel in 1999. The famed sister brand embraces flairs and charms from the Sonia Rykiel main line, including a Parisian chic vibe and inside-out stitching techniques. Sonia Rykiel , world renowned for her figure hugging 'Poor Boy Sweaters', opened her first boutique in Paris in 1968. Embracing a modern and lively aesthetic, Sonia by Sonia Rykiel pants are expertly fashioned with a colorful charm. With printed casual pants, versatile leggings and polished, tailored pants in rich colors, there are designs for all occasions.