I have a nano-spun PET hardshell. It is so breathable that I can honestly say that I find it to be more breathable than the cotton t-shirt I wear underneath, wh

I have a nano-spun PET hardshell. It is so breathable that I can honestly say that I find it to be more breathable than the cotton t-shirt I wear underneath, while also being waterproof. PET can be made to be much more breathable than common natural fabrics.