Hi,
In 1992 I took a quilting class and C & C dual duty (cotton covered poly) was the gold standard for piecing. Coats and Clark hand quilting to quilt the quilt (not sure of the content).
Flash forward to 2008 and now everyone is in the act. I have done a dozen or so since 08, I find the cotton to break easily. I am once again using C & C dual duty, I have used, washed, packed away, used etc the quilt from '92 with no problems at all.
Use what is readily available and cost effective.
Sharon