Iron - On Backing
Iron-on backing attaches the patch to the fabric by applying heat and ironing with pressure. Usually used on denim and cotton, do not use iron-on backing patches on towels, leather, polyester, nylon, and corduroy. Also, do not use this type of backing on fabrics with a rough surface. If it is used for hats, it will be better to use a hat press rather than an iron. Or the patch will be heated unevenly and cannot be firmly attached.