Originally Posted by
Tartan
Welcome from Ontario, Canada. Polyester batt is harder to quilt on a smaller sewing machine and it also shifts. With two layers of flannel and the warm and natural batt, it should be toasty. Flannel and cotton batt tends to shrink when washed but if the backing is flannel also it will shrink together. I might use a 3/8 seam allowance rather then 1/4 because flannel usually has a looser weave and frays more.
I would also wash the flannel backing before I used it. It will shrink 4-6”. I would not worry about the smaller pieces that have not been washed. They will not be able to shrink as much because of the quilting. Also I would not “go lightly” on the quilting unless that is the look you want. I would quilt it more densely to help control the shrinkage. I also would use the cotton batting for warmth, etc.