95% poly 5% elastane. Hidden back zipper closure. TWIR-WR2. TS59. Founded in 2011, Twin Sister is a label that seamlessly closes the gap between day-to-night wear through their creation of designs influenced by all corners of the world. Feminine frills, plunging necklines, and perfectly placed cut-outs are among the few signatures seen in their line, which mixes high-end appeal with fast fashion ease.