Experimenting - checking results -
I know that most woven cottons shrink - because I have measured hundreds of pieces of fabric before and after soaking/washing.
However, I do not know ahead of time which way they will shrink - most wovens shrink more in one direction than the other - or how much.
I have been told that quilting will prevent batting from shrinking. That, of course, would depend on the type of batting - but if the package says to expect 3-5% shrinkage, I would tend to believe the manufacturer. I have not personally checked this out if it is true or not.
I have also "heard" that Dual Duty (cotton covered polyester version) is "poor quality" thread. I have 20 year old quilts that are used constantly - not one popped seam or "shredded" seam line.
What have you "heard" that you took as "absolute truth" - and checked out for yourself the validity of the statement.
A couple of things I am planning to check out - at what temperature will polyester thread melt? So far, when piecing, I have not noticed any melting when I press the seams.