The Fold Over Elastic (FOE) is positioned so the centre line is aligned with the raw edge of the fabric. The left hand side of the elastic width will be underneath the fabric at this point. The right hand side of the elastic width now gets folded over on top of the fabric, so that the raw edge is entirely enclosed between the two halves of elastic. You will then zigzag stitch through this three-layered sandwich to keep it all together.