These High Quality Patches can be applied to denim, 100% cotton, and polyester/cotton blends on light and dark colored garments. They can be applied to robes, hats, bags, t-shirts, sweatshirts and so much more! Size (Approx) : 2.5 inches Backing: Iron On THESE PARTICULAR PATCHES CANNOT BE APPLIED TO ANY TYPE OF SURFACE THAT WOULD MELT WHEN HIGH HEAT IS APPLIED TO IT. The patches can be applied with an iron or a heat press. Iron Application Instructions: When applying the patches with an iron, set your iron to high heat. Using a fresh adhesive, lint-roll the surface of your garment where you will be applying your letter patches prior to prepressing to remove any lint.