This fusible bias tape is used for stabilising areas of your garment that are cut on a curve, including necklines, armholes and sleeve heads. It will help prevent fraying and also ensure these these sections of your garment from becoming over-stretched and baggy while being assembled and worn.
Use a medium iron to press it into the seam allowance of your garment (test on a scrap of your fabric first). The stitched edge of the fusible bias tape should be placed closest to the seam, allowing the unstitched edge to follow the outer curve of your cut fabric piece.
Particularly with more textured fabrics, you can also stitch just inside the stitching on the tape (on the edge towards your seam) to secure it to your fabric.
Garments incorporating fusible bias tape can be dry cleaned and washed at up to 40º according to the usual instructions for the fabric selected for your garment.