Brick and mortar or online store for buying weatherproof fabric by the yard

I am interested in starting a project that will require me to use weatherproof and breathable fabric.

I am thinking the same fabric Frog Toggs is made of or polypropylene equivalent.

Let me know if you have bought the fabric this way (by the yard) in the past.

You guys have delivered on questions like this in the past.

Thanks in advance.