This is intentional and part of the chair’s design, not a quality issue. The backrest uses a flexible structure, and the fabric is designed to wrinkle slightly so it can better adapt to movement and shape changes as the backrest responds to your body, helping maintain consistent support. The wrinkles also reduce friction between the fabric and clothing, which helps prevent wear and extend the fabric’s lifespan. If wrinkles appear during use, simply smooth the fabric gently by hand.