Made of RECYCLED polyester. If you're after an active top that is sweat-wicking and breathable but NOT clingy and body-con - try this. I got it in pink, and like the fit. Surprisingly, it works quite well for Vinyasa yoga with lots of movement and doesn't slide around too much when you do poses like down dog and wild thing. But it's especially good for a Yin or restorative practice that is slow and close to the ground.