I think the difference between 'pillowcasing' and 'birthing' a quilt is that with pillowcasing you are only sewing three sides and having tofold over the entire end. With birthing, you only leave a small opening to pull it out and this helps force it to turn the seam for you. It also helps make a nie clean corner. I use this type for anything that has 4 corners (fold n' stitch wreaths, pillows, placemats, etc) because it keeps the corners nice.