The very first quilt I made was an around the world pattern with 3.5" blocks. I took a quilting class and that's the first one! Anyway, the flannel was not pre washed and I did use only a 1/4" seam. I had no clue what a walking foot was. I pinned each square and sewed halfway and then took it out and sewed down to meet the middle. I stitched in the ditch. The quilt is 13 years old and still in daily use and washed frequently and nothing has fallen apart. Since then I have made other flannel quilts and still only used 1/4" seams and not always a walking foot and they all seem to turn out fine. Of course if you have dual feed or a walking foot that seems to me it would be easier. Good luck and I hope you can figure out a picture so we can all see!!