When I am doing custom quilting, I have been trying to complete one "motif" over the entire quilt before moving on to another. This seems easier for muscle memory coordination. It seems to make no difference whether I do borders or areas in the center of the quilt first. Rolling the quilt back and forth on the poles to work on different areas seems to stretch the backing more than the top so that the backing becomes excessively baggy in the unstitched areas. I think that this is due to the backing always being on the outer sandwich layer on the top take up roller and therefore stretching more than the pieced top. (There may be other factors going on: fabric quality, direction of grain, etc.) I try not to tension the layers excessively, especially in the pole direction.
Does anyone have recommendations to prevent this from happening?
On simpler quilting motifs, I "switch gears" and do all areas as I roll up the quilt in a single pass, but this gets complicated and doesn't work well when working with multiple designs in different areas.