The breathability of a given fabric is largely determined by how tightly the fibres are woven. The composition of those fibres is also relevant, but it's only one factor among several. read more
A thick, densely-woven cotton fabric won't breathe very well, but a thin cotton fabric with an open weave will breathe with ease. Generally, though, cotton is more useful for its moisture-wicking qualities, low cost, and high durability. read more
That being said, some cotton fabric is designed to be strong and rough, like heavy duty cotton canvas. It all depends on the weave and the finish. Great for sensitive skin: Because it is so much softer, those with sensitive skin tolerate 100% cotton better than polyester. read more