Think of the difference between working with tissue paper and working with construction paper. It is much easier to cut something from construction paper than it is from a tissue paper. That is exactly the difference between starch and sizing. Starch vs Sizing Firstly, starch and sizing are very similar, however, are not interchangeable. Commercial spray starch in a quilters spray misting bottle is made from a grain which is either wheat, rice or corn. It is basically used to add stiffness to the fabric which is very helpful when you have to prepare the fabric for cutting and piecing. It will help to make your cuts more accurate and it will also be easier to sew and match seams. It also helps to hold a crease in place in the perfect manner. Here’s why you must use spray starch: - Helps to stabilize the grains of the fabric - Adds stiffness to the fabric - Happens to allow for more control when cutting and piecing - Helps to