It doesn't say but it feels like cotton (very soft) and you can almost see through it when you hold it up to the light but not when it is on! You might see a shade of a white bra underneath it but no skin!
Sorry just got home from work...it doesn't say but it feels like cotton (very soft) and you only see through it partially when you hold it up to the light. You don't see through it when it is on.