Gutermann Fusible Thread is a time saving product, perfect for fuse basting, quilt bindings, appliques, zippers and more. Made of 50% Polyester and 50% Polyamide, this unique thread lets you sew into fabric like a regular sewing thread, then iron it and it sets your project, applique, hem, or quilt binding in place. It can be used in the bobbin or on the top thread of your sewing machine and also in the lower looped of your serger. This is a temporary bond that holds items in place before you do your final stitching.