That is pretty funny Jim. Did you buy the book, or get it from the library?

I am still trying to figure out the insistence on 100% cotton duct. I understand the properties they want, but I bet a cotton blend has those same properties, with less weight. My army fatigues are cotton/poly. They block the wind, are very rugged, weigh half as much as cotton duct, absorb half as much water, and are just as spark resistant. In fact, it is common practice to burn all the loose threads on your BDUs with a lighter. That always melts the thread, and never the fabric.

Just remember Jim, when someone has been doing it successfully their way for a long time, they aren't too keen to listen to outside advice.