What is the most breathable fabric for babies?

Considering the safety and soft texture, 100% cotton fabric is widely used for babies' clothing.

But as for the breathability and softness, modal fabric, lyocell fabric and bamboo fabric outperform cotton fabric. The good breathability will slower the growth of fungus or bacterials in the fabric. And it will make babies feel comfortable in hot days. 

Meanwhile, the modal cotton blended fabric or bamboo cottom blended fabric is also a good choice for babies.