Mr. Antony's copy is sort of confusing.

Our heaviest quality raincape made from 100% bonded cotton double texture ( cotton fabric both outside & inside the raincape ).
Similar to the rubberised double texture capes worn by bandsmen in the 60’s but softer, lighter & much less expensive !

It sure doesn't seem rubberized to me. From poking around and looking at some seams it looks like there is just one type of cloth, the very tightly woven cotton that has some sort of a bonding on the back side. No smell, no rubber feel, seems more a coating on one side.

Then the cape is sewn up with two pieces of the cotton fabric for each piece of the garment so that one piece of cotton faces out, and the other faces in and the treated sides are both inside facing each other.

As loose and airy as capes are - much like kilts - don't know that it matters much if the fabric itself breathes. Its not GoreTex, but if it does breathe some it certainly does so better than the polyesther.

Gonna take it out today and see how that all works.

Ron